H. Akintürk

Bioabsorbable metal stents for percutaneous treatment of critical recoarctation of the aorta in a newborn

In neonates and infants with critical aortic coarctation, balloon angioplasty is considered for rescue therapy of heart failure. The use of conventional stents is limited because of further vessel growth, the need of redilation, and later surgical removal. However, a novel bioabsorbable magnesium stent (AMS) might overcome such restrictions of vessel stenting in newborns. Presented is the first use of an AMS for acute treatment of a newborn with severely impaired heart function due to a long segment recoarctation after a complex surgical repair. We hypothesize that bioabsorbable stents will dramatically change the treatment of coarctation and recoarctation in newborns.

Hybrid Transcatheter–Surgical Palliation

The outcome of patients with hypoplastic left heart (HLH) is determined by many factors, particularly by the first-step palliative procedure in newborns undergoing the Norwood procedure, its Sano modification, or, rarely, through challenging biventricular repairs. Duct stenting combined with bilateral pulmonary artery banding (PAB) is a new method employed as an alternative first-step approach in a number of centers worldwide. We describe this interventional–surgical “hybrid approach” as an additional strategy for the treatment of newborns with HLH syndrome and HLH complex. Between 1998 and April, 2006, 58 newborns underwent ductal stenting and bilateral PAB. These patients underwent surgical bilateral PAB initially, followed by percutaneous duct stenting; the only exception to this were patients in whom duct stenting was performed as a rescue procedure. Various balloon-expandable and self-expandable stents with different widths and lengths were used during the 8-year period of this study. Balloon dilatation of the atrial septum was performed when indicated. This included 5 patients in whom the atrial septum was stented. Aortic arch reconstruction (AAR) combined with a bidirectional cavopulmonary connection (BCPC) was performed at a median age of 4.8 months (range, 2.6–7.5), and total cavopulmonary connection (TCPC) was performed at a median age of 3.1 years (range, 2.5–4). Nine patients were listed for heart transplantation (HTX) and transplanted with AAR when a donor heart was available. Depending on growth of left ventricular structures, biventricular repair (BVR) was performed at a median age of 7.1 months (range, 3.5–10). Overall, 8 of 58 patients (13.8%) treated by the transcatheter–surgical hybrid approach died during the study period. The mortality rate for duct stenting was 1.7% (l/58), and it was 1.7% for bilateral PAB as well. Twenty-seven patients received an AAR/BCPC; 2 of them died (7.4%). Additionally, 1 of 2 patients with AAR/BCPC died while on the waiting list for HTX, resulting in a total mortality rate of 11% with an actuarial survival rate of 89%. One patient is still awaiting AAR + BCPC. Three patients died while on the waiting list for HTX despite successful bilateral PAB and duct stenting. The 30-day mortality rate for TCPC (n = 11), HTX (n = 8), and 18 patients with BVR was 0. The actuarial survival rate for patients with BVR is 93%. Postnatal transcatheter–surgical hybrid palliation expands the surgical options for newborns with HLH. Using hybrid palliation, Norwood stage I operation can be avoided in the neonatal period, the waiting period for children scheduled for cardiac transplantation can be extended, and observation for left ventricular growth suitable for biventricular repair as well.

Heart transplantation in children and infants: Short-term outcome and long-term follow-up

Abstract: Since 1988, 82 heart transplants have been performed in 80 infants and children. Diagnoses pretransplant were: hypoplastic left heart syndrome (HLHS) (n = 43); cardiomyopathy (n = 19); endocardial fibroelastosis (n = 6); and other complex congenital heart diseases (n = 12). Age at transplantation was < 1 yr in 61 patients. Overall survival rate was 79% at 1 yr and 73% at 5 and 10 yr. To date, 20 patients have died after transplantation. Causes of death were: rejection (eight patients); right ventricular failure (four patients); transplant coronary artery disease (TCAD) (two patients); and other causes (six patients). In the majority of patients somatic growth is not impaired, and renal function is reduced (but stable) in all patients. Two patients developed post‐transplant lymphoproliferative disease, which was treated successfully. Major long‐term morbidity is neurologic deficit – severe in three patients and minor in six. TCAD was present or suspected in six surviving patients. We conclude that heart transplantation in infants and children can be performed with good early and late results. Quality of life is excellent in most patients. TCAD, however, will become an increasing problem in the long term.

Stent Implantation of the Arterial Duct in Newborns with a Truly Duct‐Dependent Pulmonary Circulation: A Single‐Center Experience with Emphasis on Aspects of the Interventional Technique

INTRODUCTION Ductal stenting for pulmonary blood supply in newborns with cyanotic congenital heart disease (CHD) might be a low risk and safe alternative to the surgical aorto-to-pulmonary artery (AP) shunt in dual-source lung perfusion. Ductal stenting in truly duct-dependent pulmonary circulation has not been evaluated. METHODS Prospective interventional and clinical follow-up trial. Ductal stenting based on variable access sites, a 2-wire technique when crossing a tortuous ductus, and use of premounted coronary stents. Primary outcome measures were procedural success and complication rates presented as early and mid-term results. RESULTS From 2003-2009, 58 duct-dependent newborns underwent ductal stenting; 27 of them were truly duct dependent, 20 had pulmonary atresia (PA)/ventricular septum defect or complex CHD, 4 had PA/intact ventricular septum, 2 had PA with Ebstein anomaly, and 1 had PA with tricuspid atresia. Ductal stenting was performed without procedure-related mortality; 3 of 27 required an acute surgical AP-shunt (stent migration in 1, acute duct obstruction in 2). During mid-term follow-up, 4 of 24 needed an AP-shunt and two others stent redilation. Three patients died prior to follow-up surgery (1 unexpectedly at home and 2 due to syndromatic disease). Fifteen patients received staged univentricular palliation, 8 had a biventricular repair, and 1 is awaiting follow-up operation. CONCLUSION Ductal stenting is a feasible, safe, and effective palliation in newborns with truly duct-dependent pulmonary circulation irrespective of duct morphology. Vasucular access from various locations is important for technical success rate. Ductal stenting is a minimally invasive procedure to achieve adequate pulmonary artery growth for subsequent palliative or corrective surgery.

Pulmonary artery banding in infants and young children with left ventricular dilated cardiomyopathy: a novel therapeutic strategy before heart transplantation.

BACKGROUND Dilated cardiomyopathy (DCM) in childhood has a considerable morbidity and mortality and high incidence of heart transplantation. Pulmonary artery banding (PAB) has been proposed in patients with corrected transposition of the great arteries to retrain the sub-pulmonic left ventricle (LV) and to improve a failing sub-aortic right ventricle. We evaluated the short-term and medium-term effects of PAB in young patients with LVDCM. METHODS A retrospective single-center observational study was performed to evaluate the possible benefits of a dilatable surgical PAB in infants and young children with LVDCM. RESULTS Reported are 12 patients (10 infants, 2 toddlers) with LVDCM referred for heart transplant who received a surgical PAB. There were no hospital deaths. Clinical functional status improved in all patients. The pressure gradient across the PAB increased within 20 days from 28 ± 7 to 43 ± 15 mm Hg. The LV ejection fraction increased from 14.5% ± 5% pre-PAB to 27% ± 13% at hospital discharge and to 47% ± 10% at 3 to 6 months. The LV end-diastolic diameter (z-score) decreased (p > 0.001) from 46 ± 6.1 (+7.0 ± 1.3) to 35 ± 15 mm (+3.0 ± 1.3) after 3 to 6 months and to 34 ± 15 mm (+1.3 ± 1.14) after a median age of 2 years (maximum 6.6 years), respectively. Plasma B-type natriuretic peptide levels decreased from 3431 ± 2610 to 288 ± 321 pg/ml at discharge and to 102 ± 96 pg/ml 22 months later. Eight children were subsequently de-banded by transcatheter technique and 6 of them are currently at Ross Heart Failure Classification for Children class I. Two patients, both with non-compaction DCM, deteriorated at 5 and 6 months after PAB debanding and finally died. CONCLUSION In young children with LVDCM and still-preserved right ventricular function, PAB led to an improvement of LV and mitral valve function by ventricular interaction.

New insights into paracrine mechanisms of human cardiac progenitor cells.

Cardiac progenitor cells (CPCs) have been shown to promote cardiac regeneration in vivo. Understanding the function of CPCs is essential for further implementation of these cells in the treatment of cardiac diseases. The present study tested the hypothesis that adult CPC exert paracrine effects that lead to an improvement in the functional characteristics of cardiomyocytes. This study also investigated whether aging (we included patients aged between 4 months and 81 years) has any effect on the paracrine mechanisms of CPC.

Mycotic pseudoaneurysm of the aorta in children.

Abstract. Mycotic pseudoaneurysm of the aorta is a rare disease in childhood. We report on two cases which were diagnosed in an unselected general pediatric population within an 8-month period. The first case was a 16-month-old toddler with a normal cardiac history who presented with purulent pericarditis due to group A steptococcus and subsequent pseudoaneurysm formation of the ascending aorta while convalescing from varicella infection. The second case was a 14-year-old girl with a previously undiagnosed coarctation of the aorta who developed a Staphylococcus aureus aortitis in the dilatated poststenotic segment with pseudoaneurysm formation and infiltration into the adjacent lung tissue. In both cases parenteral antibiotic therapy was administered over 10 and 4 days, respectively, followed by emergency surgery consisting of aneurysmectomy, coarctectomy (case 2), and in situ homograft implantation. Recovery was uneventful. In both cases early institution of a femorofemoral cardiopulmonary bypass prevented a fatal outcome despite intraoperative rupture of the pseudoaneurysm.

Factor XIII prevents development of myocardial edema in children undergoing surgery for congenital heart disease.

Abstract: In a prospective investigation of perioperative cardiac edema formation requiring a delayed sternal closure, we identified thrombin increase combined with a simultaneous decrease of factor XIII as a probable cause. After experimental studies additionally revealed that factor XIII could protect endothelial barrier function, we did another prospective randomized trial in which factor XIII or placebo was preoperatively substituted. The substitution finally showed distinct effects minimizing the incidence of myocardial swelling. Therefore, the clinical application of factor XIII may have a valuable therapeutic benefit in cases of leakage syndrome during extracorporeal circulation in congenital heart surgery.

Continuous SvO2 measurement in infants undergoing congenital heart surgery--first clinical experiences with a new fiberoptic probe.

Background:  SvO2‐guided therapy, using fiberoptic oximetric catheters can help to improve the outcome after complex congenital heart surgery especially in infants undergoing the Stage 1‐Norwood‐Procedure. So far, fiberoptic catheters have to be placed transthoracically by the surgeon into the vena cava or the pulmonary artery putting the infant at an additional risk of bleeding at the time of catheter removal.

Ventricular cardiac-assist devices in infants and children: anesthetic considerations

OBJECTIVE The application of a mechanical cardiac-assist device is now a common procedure in modern cardiac surgery in patients with end-stage failure, whereas in pediatric patients it is still a great challenge. In the recent literature, a broad range of survival and weaning rates have been reported, depending on the variety of mechanical devices and the choice of patients with different conditions before implantation or if the device is used in emergency surgery. In this article, the authors report their experience with pediatric cardiac-assist devices and the perioperative anesthesia management in this group of patients. PATIENTS AND METHODS From 1997 to 2001, 11 infants and children were supported with a left and/or right ventricular-assist device. Diagnosis included myocarditis and complex cardiac malformations (hypoplastic left heart syndrome, tetralogy of Fallot with cardiomyopathy, and combined heart defects). The data sets of all patients were recorded using the online anesthesia record-keeping system NarkoData (IMESO GmbH, Hüttenberg, Germany). The program collects all perioperative data during surgery and during a stay in the PACU, including vital signs, administered drugs, as well as the data set of the German Society of Anesthesiology and Intensive Care Medicine. RESULTS All patients were divided into 2 groups: group 1 = survivors and group 2 = nonsurvivors. A total of 5 patients were in group 1, and group 2 consisted of 6 patients. The duration of anesthesia in group 1 patients (173.2 +/- 95.1 minutes) was significantly (p < 0.05) shorter than in group 2 (631.1 +/- 258.8 minutes) as well as the amount of packed red cells (group 1= 540.5 +/- 150.3 mL, group 2 = 880.6 +/- 400.3 mL). Cardiopulmonary bypass before implantation of a VAD was necessary only in 2 patients from group 1, whereas 5 patients in group 2 were on pump during the procedure. The rate of aortic cross-clamping was also significantly lower in group 1 than in group 2 (p < 0.05). CONCLUSIONS The surgical outcome depends on the patients condition at the time of surgery. Emergency surgery, preoperative multiorgan failure, and the need for an extracorporeal circulation with aortic cross-clamping seem to predict a negative outcome in this group of patients.