Decellularized aortic homografts for aortic valve and aorta ascendens replacement.

OBJECTIVES: The choice of valve prosthesis for aortic valve replacement (AVR) in young patients is challenging. Decellularized pulmonary homografts (DPHs) have shown excellent results in pulmonary position. Here, we report our early clinical results using decellularized aortic valve homografts (DAHs) for AVR in children and mainly young adults. METHODS: This prospective observational study included all 69 patients (44 males) operated from February 2008 to September 2015, with a mean age of 19.7 ± 14.6 years (range 0.2-65.3 years). In 18 patients, a long DAH was used for simultaneous replacement of a dilated ascending aorta as an extended aortic root replacement (EARR). Four patients received simultaneous pulmonary valve replacement with DPH. RESULTS: Thirty-nine patients (57%) had a total of 62 previous operations. The mean aortic cross-clamp time in isolated cases was 129 ± 41 min. There was 1 conduit-unrelated death. The mean DAH diameter was 22.4 ± 3.7 mm (range, 10-29 mm), the average peak gradient was 14 ± 15 mmHg and the mean aortic regurgitation grade (0.5 = trace, 1 = mild) was 0.6 ± 0.5. The mean effective orifice area (EOA) of 25 mm diameter DAH was 3.07 ± 0.7 cm(2). DAH annulus z-values were 1.1 ± 1.1 at implantation and 0.7 ± 1.3 at the last follow-up. The last mean left ventricle ejection fraction and left ventricle end diastolic volume index was 63 ± 7% and 78 ± 16 ml/m(2) body surface area, respectively. To date, no dilatation has been observed at any level of the graft during follow-up; however, the observational time is short (140.4 years in total, mean 2.0 ± 1.8 years, maximum 7.6 years). One small DAH (10 mm at implantation) had to be explanted due to subvalvular stenosis and developing regurgitation after 4.5 years and was replaced with a 17 mm DAH without complication. No calcification of the explanted graft was noticed intraoperatively and after histological analysis, which revealed extensive recellularization without inflammation. CONCLUSIONS: DAHs withstand systemic circulation, provide outstanding EOA and appear as an alternative to conventional grafts for AVR in young patients. EARR using DAH is a further option in aortic valve disease associated with aorta ascendens dilatation as it avoids the use of any prosthetic material.

Surgical Treatment of Thoracic Aortic Aneurysms in Patients with Congenital Heart Disease.

BACKGROUND: This study we evaluate our results for surgical treatment of thoracic aortic aneurysms in patients with congenital heart disease. PATIENTS AND METHODS: Fifty patients aged between 12 and 71 years were treated for 51 thoracic aortic aneurysms. Forty-four of the patients developed aneurysms in the ascending aorta and seven developed aneurysms in the descending aorta. The underlying diseases for ascending aortic aneurysms included 16 congenital aortic stenosis, 16 bicuspid aortic valves, 4 transposition of the great arteries, 3 tetralogy of Fallot, 2 truncus arteriosus communis, and 3 other diseases. Patients with connective tissue disorders were excluded. All descending aortic aneurysms developed late after coarctation repair. The time interval between the correction and aneurysm operations was 15 years in ascending aneurysms and 28 years in descending aneurysms. RESULTS: The operative procedures for 44 ascending aortic aneurysms included 38 ascending aortic replacements, with or without aortic valve replacement (including 31 conduits), and 6 David operations. Graft replacement was undertaken for the seven descending aortic aneurysms. There were two hospital deaths. Forty-eight hospital survivors were in New York Heart Association functional class II or less at follow-up, which was conducted up to a maximum of 8 years after the procedure. All patients were free from reoperation and thromboembolic events. Aortic valve function was good in all six patients after the valve-sparing operation. CONCLUSION: Thoracic aortic aneurysms in patients with congenital heart disease is highly associated with bicuspid aortic valve and aortic coarctation. For ascending aortic aneurysms, conduit replacement is the method of choice. The David procedure provides good results in selected patients. For descending aortic aneurysms, graft replacement is the preferred procedure. The relatively late development of thoracic aortic aneurysms indicates that long-term follow-up in patients with congenital heart disease, especially in patients with bicuspid aortic valve and aortic coarctation, is essential.

Semilunar valve replacement with decellularized homograft after Damus-Kaye-Stansel anastomosis and fontan procedure.

We describe a patient in whom severe neoaortic (anatomic pulmonary) valve regurgitation developed late after Damus-Kaye-Stansel anastomosis and Fontan operation. The valve was replaced with a fresh decellularized homograft, which we developed and applied in the normal pulmonary and aortic position in more than 100 patients. During follow-up of more than 2 years, the valve function is excellent, and no infectious or thromboembolic complications were seen. The decellularized homograft seems to be an ideal material in this situation.

A modified technique of Konno aortoventriculoplasty for redo aortic valve replacement procedures.

This article puts forward a modified technique of Konno aortoventriculoplasty for repeat procedures. After incision of the ventricular septum, this approach involves aortic valve replacement using a mechanical valved conduit, reimplantation of the coronary arteries, and graft replacement of the ascending aorta. This modification allows the removal of the diseased ascending aortic wall caused by a previous patch enlargement or poststenotic dilation.

Early systemic cellular immune response in children and young adults receiving decellularized fresh allografts for pulmonary valve replacement.

OBJECTIVES: The longevity of homografts is determined by the activation of the recipients' immune system resulting from allogenic antigen exposition. Fresh decellularized pulmonary homografts (DPH) have shown promising early results in pulmonary valve replacement in children and young adults and could potentially avoid significant activation of the immune system, as more than 99% of the donor DNA is removed during the decellularization process. While the humoral immune response to decellularized allografts has been studied, detailed information on the more significant cellular immune response is currently lacking. METHODS AND RESULTS: Peripheral blood samples were obtained from patients undergoing pulmonary valve replacement with DPH before, after, and for approximately 3 years after implantation. Absolute counts and percentages of mature T- (CD3(+)), B- (CD19(+)), and natural killer- (CD16(+)/CD56(+)) cells, as well as T helper- (CD4(+)) and cytotoxic T-cell- (CD8(+)) subsets, were determined by fluorescence-activated cell sorting (FACS). Between May 2009 and September 2013, 199 blood samples taken from 47 patients with a mean age at DPH implantation of 16.6±10.8 years were analyzed. The hemodynamic performance of DPH was excellent in all but one patient, and no valve-related deaths or conduit explantations were observed. The short-term follow up revealed a significant postoperative decrease in cell counts of most subtypes with reconstitution after 3 months. Continued assessment did not show any significant deviations in cell counts from their baseline values. CONCLUSION: The absence of cellular immune response in patients receiving DPH supports the concept that decellularization can provide a basis for autologous regeneration.

Use of latissimus dorsi pedicled myocutaneous flap for reconstruction in the chest area of an 8-month-old female infant with ectopia cordis.

Ectopia cordis (EC) is characterized by a complete or partial malposition of the heart outside the thorax. Despite the interdisciplinary treatment, the repair of EC is still very difficult and offers new surgical challenges because of its complexity and various combinations with other anomalies. We report the successful outcome after using a pedicled latissimus dorsi flap in reconstructive surgery in the setting of chronic wound dehiscence in an 8-month-old female infant born with a thoracic EC and omphalocele.

Surgical repair of partial anomalous pulmonary venous connection shunting from left atrium to innominate vein.

Partial anomalous pulmonary venous connection (PAPVC) causes a left-to-right shunt from the anomalous pulmonary vein (PV) to a systemic vein. We report an uncommon adult case of PAPVC, in which the left upper PV drained into both the innominate vein and the left atrium (LA), demonstrating retrograde shunting from the LA to the innominate vein. The anomaly was surgically repaired.

Aortic root replacement in a patient with bicuspid pulmonary valve late after arterial switch operation.

Mild to moderate neoaortic root dilatation late after arterial switch operation (ASO) is a well-documented morbidity, but rarely needs surgical replacement. Here, we report on a 22-year-old man, who developed marked dilatation of neoaortic root and needed an aortic root replacement with mechanical conduit. His aortic valve was bicuspid. Only three cases have been reported for surgical replacement of aortic root after ASO, and two of them had bicuspid neoaortic valves. We suspect that a bicuspid neoaortic valve may be a risk factor for marked dilatation of the aortic root late after ASO.

Risk factors for distal Contegra stenosis: results of a prospective European multicentre study.

Objectives The EUCon study was designed to identify risk factors for distal anastomotic stenosis after bovine jugular vein (Contegra) implantation in children. Methods Between March 2006 and August 2008, 104 devices were implanted in nine European centers. Preoperative, intraoperative, and follow-up data (at discharge, 6, 12, 24 months) including standardized echocardiography were prospectively registered, source data verified and collected in a central database. Main endpoint was distal stenosis (either postvalvular gradient of ≥50 mm Hg or need for intervention for distal stenosis). Eight potential risk factors (age <2 years, diagnosis, running suture, use of glue, flapless anastomosis, oversizing less than + 2 z, anticoagulation, implantation site) were investigated. Cox regression, decision tree analyses, and "Clustering by Response" were applied. Results Patient age ranged from 0 to18 years, mean 6.0 ± 6.1, median 3.2 years. Implantation reasons: 88% congenital malformations, 12% Ross operations. Follow-up was 88.3% complete. Durability (freedom from death, reoperation, degeneration, endocarditis, and explantation) compared well to corresponding homograft literature. Sixteen patients reached study endpoints. Age <2 years was the only invariably significant risk factor (p = 0.044); "Clustering By Response" found young anticoagulated patients with oversized conduits to be at a higher risk than the others (p = 0.018, OR = 3.2). Conclusion Patient age is the main risk factor for development of distal anastomosis stenosis after Contegra implantation. The influence of the other investigated factors is too small to be proven in 104 patients after 2 years, or other risk factors must be taken into consideration to explain outcome differences among recipients under 2 years.

Removal of temporary pacemaker after cardiac surgery in infants: A harmless procedure?

External pacemakers (PM) via temporary epicardial leads are routinely applied to infants and children during heart surgery, which usually, after an uneventful post surgical course, can be removed without complications. We report about two infants with complex congenital heart defects after cardiac surgery (arterial switch and Mustard operation for Transposition of the great arteries). Intraoperative these patients received temporary epicardial PM wires. Thirteen and 18 days post surgery, respectively, the PM wires were removed under electrocardiogram (ECG) monitoring. The patients showed acute ECG changes in terms of significant ST elevation during and after removing their pacing wires. Clinically, patients were stable and subsequent echocardiographic examination showed no evidence of myocardial dysfunction or pericardial effusion. In the course of time, patients showed no signs of arrhythmia or abnormal ECG changes. The decision to place temporary pacing wires during the cardiac surgery in patients with congenital heart defects should be considered carefully and their removal should occur under ECG monitoring as soon as the situation of the patient allows. It should be taken into consideration that a complication like this case may be related to delayed removal of temporary PM's leads.

Use of fresh decellularized allografts for pulmonary valve replacement may reduce the reoperation rate in children and young adults: early report.

BACKGROUND: Degeneration of xenografts or homografts is a major cause for reoperation in young patients after pulmonary valve replacement. We present the early results of fresh decellularized pulmonary homografts (DPH) implantation compared with glutaraldehyde-fixed bovine jugular vein (BJV) and cryopreserved homografts (CH). METHODS AND RESULTS: Thirty-eight patients with DPH in pulmonary position were consecutively evaluated during the follow-up (up to 5 years) including medical examination, echocardiography, and MRI. These patients were matched according to age and pathology and compared with BJV (n=38) and CH (n=38) recipients. In contrast to BJV and CH groups, echocardiography revealed no increase of transvalvular gradient, cusp thickening, or aneurysmatic dilatation in DPH patients. Over time, DPH valve annulus diameters converge toward normal z-values. Five-year freedom from explantation was 100% for DPH and 86 ± 8% and 88 ± 7% for BJV and CH conduits, respectively. Additionally, MRI investigations in 17 DPH patients with follow-up time >2 years were compared with MRI data of 20 BJV recipients. Both patient groups (DPH and BJV) were at comparable ages (mean, 12.7 ± 6.1 versus 13.0 ± 3.0 years) and have comparable follow-up time (3.7 ± 1.0 versus 2.7 ± 0.9 years). In DPH patients, the mean transvalvular gradient was significantly (P=0.001) lower (11 mm Hg) compared with the BJV group (23.2 mm Hg). Regurgitation fraction was 14 ± 3% and 4 ± 5% in DPH and BJV groups, respectively. In 3 DPH recipients, moderate regurgitation was documented after surgery and remained unchanged in follow-up. CONCLUSIONS: In contrast to conventional homografts and xenografts, decellularized fresh allograft valves showed improved freedom from explantation, provided low gradients in follow-up, and exhibited adaptive growth.

Intrapericardial migration of dislodged sternal struts as late complication of open pectus excavatum repairs.

UNLABELLED: We present a case of sternal steel strut dislodgement and migration in a patient undergoing Ravitch repair for pectus excavatum (PE) 37 years ago. Broken struts perforated the right ventricle and right ventricular outflow tract (RVOT) and additionally migrated into the left upper lobar bronchus.Dislodged sternal struts represent rare complications after surgical repair of patients suffering from pectus excavatum. Reviewing the literature, only five cases of intrapericardial migration of dislodged sternal struts or wires have been reported so far.In our case, the first strut was removed from the airways through a left antero-lateral thoracotomy. Using cardiopulmonary bypass, a second strut was removed via ventriculotomy. These life-threatening sequelae underscore the importance of postoperative follow-up and early removal of osteosynthetic materials used in open PE repair. Accurate preoperative localization of migrated materials and availability of CPB support are crucial for successful surgical removal. INTRODUCTION: The migration of dislodged sternal steel struts or wires into the pericardium and cardiac cavities is a rare but life-threatening complication of open pectus excavatum (PE) repair 1. Removal of these materials poses a challenge for cardiothoracic surgeons. Herein, the authors report a case of migration of dislodged steel struts through the right ventricle and right ventricular outflow tract (RVOT) into the left upper lobar bronchus in a patient who underwent Ravitch repair 37 years ago.

Functional total anomalous pulmonary venous drainage by left atrium-to-superior vena cava shunt.

Total anomalous pulmonary venous connection is occasionally associated with a functional single ventricle and is thought to be a risk for the staged Fontan approach. We report a patient with a very rare presentation of mitral atresia and intact atrial septum with physiologically total anomalous pulmonary venous drainage by a connecting vein between the left atrium and the superior vena cava. A surgical atrioseptectomy as a functional repair of total anomalous pulmonary venous connection and pulmonary artery banding was successfully performed as the first palliation for Fontan completion.

Long-term morbidity and quality of life after surgical repair of transposition of the great arteries: atrial versus arterial switch operation.

Since a growing number of patients after surgical repair of transposition of the great arteries (TGA) survive until adulthood the focus of attention has shifted to the management of associated long-term morbidity and quality of life (QoL). Therefore, we reviewed all patients that underwent surgical repair of TGA at our institution and compared long-term results after atrial and arterial switch operation. Between 1973 and 2000, a total of 302 patients underwent either atrial switch operation (n=222) or arterial switch operation (n=80). Mean follow-up was 14.5±10.1 years. The arterial switch repair was associated with a higher early mortality whereas long-term survival was comparable between both groups. Postoperative arrhythmias including loss of sinus rhythm and pacemaker implantation occurred significantly more often after atrial switch repair. There was a trend towards a more favourable outcome of the arterial switch group concerning freedom from re-interventions, severe systemic ventricular dysfunction and need for heart failure medication. However, also the arterial switch operation was associated with an increased incidence of loss of sinus rhythm and neo-aortic valve regurgitation during late follow-up. Health related QoL according to the SF-36 questionnaire was not significantly different between both groups and comparable to a healthy population.

Pulmonary valve replacement in chronic pulmonary regurgitation in adults with congenital heart disease: impact of preoperative QRS-duration and NT-proBNP levels on postoperative right ventricular function.

BACKGROUND: Chronic severe pulmonary regurgitation (PR) causes progressive right ventricular (RV) dysfunction and heart failure. Parameters defining the optimal time point for surgery of chronic PR are lacking. The present study prospectively evaluated the impact of preoperative clinical parameters, cardiorespiratory function, QRS duration and NT-proBNP levels on post operative RV function and volumes assessed by cardiac magnetic resonance imaging (CMR) in patients with chronic severe PR undergoing pulmonary valve replacement. METHODS AND RESULTS: CMR was performed pre- and 6 months postoperatively in 27 patients (23.6 ± 2.9 years, 15 women) with severe PR. Postoperatively, RV endsystolic (RVESVI) and enddiastolic volume indices (RVEDVI) decreased significantly (RVESVI pre 78.2 ± 20.4 ml/m² BSA vs. RVESVI post 52.2 ± 16.8 ml/m²BSA, p<0.001; RVEDVI pre 150.7 ± 27.7 ml/m²BSA vs. RVEDVI post 105.7 ± 26.7 ml/m²BSA; p<0,001). With increasing preoperative QRS-duration, postoperative RVEF decreased significantly (r=-0.57; p<0.005). Preoperative QRS-duration smaller than the median (156 ms) predicted an improved RVEF compared to QRS-duration≥ 156 ms (54.9% vs 46.8%, p<0.05). Multivariate analysis identified preoperative QRS duration as an independent predictor of postoperative RVEF (p<0.005). NT-proBNP levels correlated with changes in RVEDI (r=0.58 p<0,005) and RVESVI (r=0.63; p<0,0001). Multivariate analysis identified NT-proBNP levels prior to PVR as an independent predictor of volume changes (p<0.05). CONCLUSION: Valve replacement in severe pulmonary regurgitation causes significant reduction of RV volumes. Both, preoperative NT-proBNP level elevation and QRS prolongation indicate patients with poorer outcome regarding RV function and volumes.

Regression of marked myocardial sinusoids associated with hypoplastic left heart syndrome during staged Fontan approach.

The anatomic subtype of mitral stenosis, aortic atresia, and myocardial sinusoids is reported to be associated with increased mortality for staged repair for hypoplastic left heart syndrome. We herein report a very rare case of this subtype of hypoplastic left heart syndrome presenting with marked myocardial sinusoids in the left ventricle, which nearly disappeared after successful Fontan completion. Our successful experience suggests marked myocardial sinusoids per se are not a risk factor for surgical palliation in hypoplastic left heart syndrome.

Physical stress testing of bovine jugular veins using magnetic resonance imaging, echocardiography and electrical velocimetry.

Bovine jugular veins (BJVs) (Contegra) are valve-bearing pulmonary artery substitutes. Their valves have higher profiles than human pulmonary valves; this might result in less optimal performance. Therefore, we investigated the impact of stress and undersizing on conduit performance with ergometry, echocardiography and magnetic resonance imaging (MRI). Between April 2007 and June 2008, 20 BJV recipients (age 7.9-19.6 years) underwent spiroergometry and subsequent echocardiography; after due rest, ergometry was repeated and followed by MRI during recovery. A year later, exams were repeated. Data was evaluated as follows: comparison of stress related maximal individual valve performance changes (magnetic resonance: exercise induced average stroke volume changes by 61+/-49%; mean insufficiency increased by 2% in patients with <1% rest insufficiency and by 8% after rest insufficiency of >10%; the average rest gradient of 24+/-11 mmHg rose to 40+/-20 mmHg), and stratification of pooled observations by regurgitation fraction, insufficiency grades and z-values (insufficiency rose with increasing heart rate and decreasing stroke volume; undersizing increased gradients during recovery by 7+/-0.7 mmHg/z-value). Contegras high-profile valves tolerate stress without performance drop. Stress induced changes of insufficiency and gradient were clinically not significant, but sufficient to distort examination results; therefore, constant examination conditions are indispensable for a correct follow-up.