Factors associated with perioperative mortality in children and adolescents operated for tetralogy of Fallot: A sub-Saharan experience.

BACKGROUND: Patients with tetralogy of Fallot are now surviving to adulthood with timely surgical intervention. However, many patients in low-income countries have no access to surgical intervention. This paper reports the surgical access and perioperative mortality in a sub-Saharan center that was mainly dependent on visiting teams. METHODS: We reviewed records of patients operated from January 2009 to December 2014. We examined perioperative outcomes, primarily focusing on factors associated with perioperative mortality. RESULTS: During this period, 62 patients underwent surgery. Fifty-seven (91.9%) underwent primary repair, while 5 (6.5%) underwent palliative shunt surgery. Of the five patients with shunt surgery, four ultimately underwent total repair. Eight (12.9%) patients died during the perioperative period. Factors associated with perioperative mortality include repeated preoperative phlebotomy procedures (P < .001), repeated runs and long cardiopulmonary bypass time (P < .001), and aortic cross-clamp time (P < .001), narrow pulmonary artery (PA) valve annulus diameter (P = .022), narrow distal main PA diameter (P = .039), narrow left branch PA diameter (P = .049), and narrow right PA diameter (P = .039). Of these factors, cardiopulmonary bypass time/aortic cross-clamp time and pulmonary valve annulus diameter less than three SD were independently associated with perioperative mortality. CONCLUSION: In this series of consecutive patients operated by a variety of humanitarian surgical teams, cardiopulmonary bypass time/aortic cross-clamp time, and pulmonary valve annulus diameter less than three SD were independently associated with perioperative mortality risk. As some of these factors are modifiable, we suggest that they should be considered during patient selection and at the time of surgical intervention.

No evidence for mosaic pathogenic copy number variations in cardiac tissue from patients with congenital heart malformations.

The aim of this study was to investigate if pathogenic copy number variations (CNVs) are present in mosaic form in patients with congenital heart malformations. We have collected cardiac tissue and blood samples from 23 patients with congenital heart malformations that underwent cardiac surgery and screened for mosaic gene dose alterations restricted to cardiac tissue using array comparative genomic hybridization (array CGH). We did not find evidence of CNVs in mosaic form after array CGH analysis. Pathogenic CNVs that were present in both cardiac tissue and blood were detected in 2/23 patients (9%), and in addition we found several constitutional CNVs of unclear clinical significance. This is the first study investigating mosaicism for CNVs in heart tissue compared to peripheral blood and the results do not indicate that pathogenic mosaic copy number changes are common in patients with heart malformations. Importantly, in line with previous studies, our results show that constitutional pathogenic CNVs are important factors contributing to congenital heart malformations.

Smart placement of a mediastinal drain in a neonate who requires a postoperative open sternum.

Crowding of the mediastinum after complex cardiac repair procedures in neonates and young children is a frequent problem. To create space, the sternal wound is kept open, commonly with a plastic stent, for later closure. Despite this maneuver, space is still an issue, and appropriate placement of the mediastinal drain can become a challenge. In this article we describe a simple and effective way to eliminate the problem. Holes are made in the sternal stent, and the drain is pulled through these holes. The drain is elevated away from the heart surface and does not contribute to the crowding.

Early surgical experience of right ventricular outflow reconstruction with the RVOT Elan conduit in adults and adolescents with congenital heart disease.

OBJECTIVE: Several types of valves and valved conduits have been developed for right ventricular outflow tract reconstruction and yet no one has provided prolonged satisfactory hemodynamic performance. The RVOT Elan is a bioprosthetic heart valve conduit constructed from a vascular graft and a porcine stentless valve indicated specifically for right ventricular outflow tract reconstruction. The present study aimed to evaluate the early clinical and hemodynamic results following implantation of the RVOT Elan in adults and adolescents with congenitally corrected right ventricular outflow tract anomalies requiring reintervention. DESIGN: Nineteen consecutive patients underwent right ventricular outflow reconstruction with the RVOT Elan between June 2012 and May 2013 in a nationally centralized center for surgery of patients with congenital heart disease. Pulmonic transvalvular gradients were evaluated with echocardiograms at discharge. Postoperative data on adverse clinical events were obtained from patient records. Follow-up was performed in October 2013 and was 100% complete (mean 331 ± 102, median 315 days). RESULTS: There were no intraoperative deaths. Survival at 30 days was 100% and there were no late deaths. The mean gradients were 14, 15, 13 mm Hg for the 21, 23, and 25 mm valve size, respectively. There were no cases of endocarditis or valve thrombosis. Freedom from reoperation for any cause was 100%. Freedom from cardiovascular adverse events was 94.4% (data 90.5% complete). CONCLUSIONS: The RVOT Elan demonstrates excellent early clinical and favorable hemodynamic results, with low transvalvular gradients, good flow characteristics, and a complete freedom from reoperation. Ease of implantation is evidenced by favorable ischemic times. Long-term results are awaited.

Validation of an ultrasound dilution technology for cardiac output measurement and shunt detection in infants and children.

OBJECTIVE: To validate cardiac output measurements by ultrasound dilution technology (COstatus monitor) against those obtained by a transit-time ultrasound technology with a perivascular flow probe and to investigate ultrasound dilution ability to estimate pulmonary to systemic blood flow ratio in children. DESIGN: Prospective observational clinical trial. SETTING: Pediatric cardiac operating theater in a university hospital. MATERIAL AND METHODS: In 21 children (6.1 ± 2.6 kg, mean ± SD) undergoing heart surgery, cardiac output was simultaneously recorded by ultrasound dilution (extracorporeal arteriovenous loop connected to existing arterial and central venous catheters) and a transit-time ultrasound probe applied to the ascending aorta, and when possible, the main pulmonary artery. The pulmonary to systemic blood flow ratio estimated from ultrasound dilution curve analysis was compared with that estimated from transit-time ultrasound technology. RESULTS: Bland-Altman analysis of the whole cohort (90 pairs, before and after surgery) showed a bias between transit-time ultrasound (1.01 ± 0.47 L/min) and ultrasound dilution technology (1.03 ± 0.51 L/min) of -0.02 L/min, limits of agreement -0.3 to 0.3 L/min, and percentage error of 31%. In children with no residual shunts, the bias was -0.04 L/min, limits of agreement -0.28 to 0.2 L/min, and percentage error 19%. The pooled co efficient of variation was for the whole cohort 3.5% (transit-time ultrasound) and 6.3% (ultrasound dilution), and in children without shunt, it was 2.9% (transit-time ultrasound) and 4% (ultrasound dilution), respectively. Ultrasound dilution identified the presence of shunts (pulmonary to systemic blood flow ≠ 1) with a sensitivity of 100% and a specificity of 92%. Mean pulmonary to systemic blood flow ratio by transit-time ultrasound was 2.6 ± 1.0 and by ultrasound dilution 2.2 ± 0.7 (not significant). CONCLUSION: The COstatus monitor is a reliable technique to measure cardiac output in children with high sensitivity and specificity for detecting the presence of shunts.

Coronary flow and reactivity, but not arrhythmia vulnerability, are affected by cardioplegia during cardiopulmonary bypass in piglets.

BACKGROUND: Surgery under cardiopulmonary bypass (CPB) is still associated with significant cardiovascular morbidity in both pediatric and adult patients but the mechanisms are not fully understood. Abnormalities in coronary flow and function have been suggested to play an important role. Prior studies suggest protective effects on coronary and myocardial function by short intravenous (i.v.) infusion of cyclosporine A before CPB. METHODS: Barrier-bred piglets (10-12 kg, n=20) underwent CPB for 45 min, with or without antegrade administration of cardioplegic solution. Prior to CPB, half of the animals in each group received an i.v. infusion of 100 mg/kg cyclosporine A. The left anterior descending coronary flow velocity responses to adenosine, serotonin, and atrial pacing, as well as left ventricular function and postsurgical vulnerability to atrial fibrillation (Afib) were assessed by intracoronary Doppler, epicardial echocardiography, and in vivo electrophysiological study, before and 8 hours after surgery. Plasma C-reactive protein (CRP) and fibrinogen were measured at both time-points. RESULTS: Cyclosporine infusion did not influence any of the studied variables (p>0.4). Coronary peak flow velocity (cPFV) rose significantly after surgery especially in the cardioplegia group (p<0.01 vs. non-cardioplegia group and pre-surgery). cPFV responses to adenosine, but not to serotonin, tended to decrease (p=0.06) after surgery only in cardioplegia group (p=0.06; p=0.8 in non-cardioplegia group vs pre-surgery). Also, cPFV response to atrial pacing was lower in the cardioplegia than in the non-cardioplegia group (p=0.02). Neither vulnerability nor duration of induced Afib after CPB differed between groups (Chi-square p=0.4). Cyclosporine had no significant effect on coronary indexes or arrhythmia vulnerability (p>0.4). There was no difference in systolic myocardial function between groups at any time point. CONCLUSION: In piglets, CPB with cardioplegia was associated with profound abnormalities in coronary vasomotor tone and receptor-related flow regulation, whereas arrhythmia vulnerability appeared to be comparable with that in non-cardioplegia group. In this study, preconditioning with cyclosporine had no detectable protective effect on coronary circulation or arrhythmia vulnerability after CPB.

Total anomalous pulmonary venous connection: outcome of postoperative pulmonary venous obstruction.

OBJECTIVE: Pulmonary venous obstruction (PVO) is an important cause of late mortality in total anomalous pulmonary venous connection (TAPVC). We aimed to describe current practices for the management of postoperative PVO and the efficacy of the different interventional procedures. METHODS: We conducted a retrospective international collaborative population-based study involving 19 pediatric cardiac centers in the United Kingdom, Ireland, and Sweden. Patients with TAPVC born between January 1, 1998, and December 31, 2004, were identified. Patients with functionally univentricular circulation or atrial isomerism were excluded. All available data and images were reviewed. RESULTS: Of 406 patients undergoing repair of TAPVC, 71 (17.5%) had postoperative PVO. The diagnosis was made within 6 months of surgery in 59 (83%) of the 71 patients. In 12, serial imaging documented change in appearance of the pulmonary veins. Good-sized pulmonary veins can progress to diffusely small veins and rarely atresia. Patients presenting after 6 months had less severe disease; all are alive at most recent follow-up. Fifty-six (13.8%) of 406 patients underwent intervention for postoperative PVO: 44 had surgical treatment and 12 had an initial catheter intervention. One half underwent 1 or more reinterventions. Three-year survival for patients with postoperative PVO was 58.7% (95% confidence intervals, 46.2%-69.2%) with a trend that those having a surgical strategy did better (P = .083). Risk factors for death included earlier presentation after TAPVC repair, diffusely small pulmonary veins at presentation of postoperative PVO, and an increased number of lung segments affected by obstruction. CONCLUSIONS: Postoperative PVO tends to appear in the first 6 months after TAPVC repair and can be progressive. Early intervention for PVO may be indicated before irreversible secondary changes occur.

Heart rate variability in children with Fontan circulation: lateral tunnel and extracardiac conduit.

The technique in Fontan surgery has developed from the lateral tunnel (LT) toward the extracardiac conduit (EC) used to reduce long-term complications such as atrial arrhythmia and sinus node dysfunction. Heart rate variability (HRV) examines cardiac nervous activity controlling the sinus node. This study aimed to investigate HRV in a cohort of children with univentricular hearts, focusing on the relation between HRV and surgical procedure. For 112 children with Fontan circulation, HRV was analyzed using power spectral analysis. Spectral power was determined in three regions: very-low-frequency (VLF), low-frequency (LF), and high-frequency (HF) regions. Patients were compared with 66 healthy controls subject. Patients with LT were compared with patients who had EC. The children with Fontan circulation showed a significantly reduced HRV including total power (P < 0.0001), VLF (P < 0.0001), LF (P < 0.0001), and HF (P = 0.001) compared with the control subjects. The LT and EC patients did not differ significantly. Reduced HRV was found in both the LT and EC patients. In terms of HRV reduction, EC was not superior to LT.

Total anomalous pulmonary venous connection: morphology and outcome from an international population-based study.

BACKGROUND: late mortality after repair of total anomalous pulmonary venous connection is frequently associated with pulmonary venous obstruction (PVO). We aimed to describe the morphological spectrum of total anomalous pulmonary venous connection and identify risk factors for death and postoperative PVO. METHODS AND RESULTS: we conducted a retrospective, international, collaborative, population-based study involving all 19 pediatric cardiac centers in the United Kingdom, Ireland, and Sweden. All infants with total anomalous pulmonary venous connection born between 1998 and 2004 were identified. Cases with functionally univentricular circulations or atrial isomerism were excluded. All available data and imaging were reviewed. Of 422 live-born cases, 205 (48.6%) had supracardiac, 110 (26.1%) had infracardiac, 67 (15.9%) had cardiac, and 37 (8.8%) had mixed connections. There were 2 cases (0.5%) of common pulmonary vein atresia. Some patients had extremely hypoplastic veins or, rarely, discrete stenosis of the individual veins. Sixty (14.2%) had associated cardiac anomalies. Sixteen died before intervention. Three-year survival for surgically treated patients was 85.2% (95% confidence interval 81.3% to 88.4%). Risk factors for death in multivariable analysis comprised earlier age at surgery, hypoplastic/stenotic pulmonary veins, associated complex cardiac lesions, postoperative pulmonary hypertension, and postoperative PVO. Sixty (14.8%) of the 406 patients undergoing total anomalous pulmonary venous connection repair had postoperative PVO that required reintervention. Three-year survival after initial surgery for patients with postoperative PVO was 58.7% (95% confidence interval 46.2% to 69.2%). Risk factors for postoperative PVO comprised preoperative hypoplastic/stenotic pulmonary veins and absence of a common confluence. CONCLUSIONS: preoperative clinical and morphological features are important risk factors for postoperative PVO and survival.

Use of pediatric Berlin Heart EXCOR biventricular device as a bridge to retransplantation in a 10-month-old infant with acute graft failure after cardiac transplantation.

We report the implantation of the Berlin Heart EXCOR (Berlin Heart, Berlin, Germany) as a pediatric biventricular assist device in a 10-month-old boy with primary graft failure after cardiac transplantation. The EXCOR was successfully used as a bridge to cardiac retransplantation. The pneumatically driven paracorporeal device supported the patient for 165 days until another suitable heart was obtained.

Outcome of surgical commissurotomy for aortic valve stenosis in early infancy.

BACKGROUND: The method of treatment of aortic valve stenosis in early infancy is still controversial. This study was performed to evaluate short-term and long-term outcome in our center during a 14-year period. METHODS: Between 1991 and 2004, 64 consecutive patients younger than 3 months old underwent open surgical commissurotomy because of aortic valve stenosis. Median age was 18 days (range, 1 to 79 days), and median weight was 3.6 kg (range, 1.9 to 6.7 kg). Left ventricular function was good in 44 patients (69%), depressed in 12 (19%), and poor in 8 (12%). The study ended in July 2005. Median follow-up time was 4.1 years (range, 0.4 to 13.6 years). RESULTS: The 30-day mortality was 3 of 64 patients and late mortality was 3 of 61, and the respective mortality in patients younger than 1 month old was 2 of 41 and 2 of 39. There was no early mortality after 1993 and no late mortality after 1999. Thirteen patients required reoperation. Median time to reoperation was 4.3 years (range, 0.2 to 11.3 years) and to aortic valve replacement (7 Ross and 1 homograft) was 6.9 years (range, 1.6 to 9.7 years). At the last follow-up, all had good left ventricular function and 57 of 58 had an ability index of 1. CONCLUSIONS: Surgical commissurotomy for aortic valve stenosis during the first 3 months of life can be done with low mortality and morbidity. The risk for early recurrent stenosis or regurgitation is low, and the need for aortic valve replacement can, in most cases, be delayed until the child is older. The long-term functional ability is excellent.

Heart transplantation across antibodies against human leukocyte antigen and ABO-post-transplant follow-up of donor reactive antibodies.

BACKGROUND: We have successfully performed heart transplantation despite the most unfavourable risk factors for graft and patient survival: the presence of a high level of antibodies (Abs) against the donor's human leukocyte antigens (HLA) class I/II and blood group A1 antigens. The present study concerns post-transplant follow-up and characterization of donor reactive antibodies (DRA). METHODS: Pre-transplant treatment consisted of mycophenolate mofetil (MMF), prednisolone, tacrolimus, intravenous immunoglobulin (IVIG), rituximab, protein-A immunoadsorption (PAIA) and per-operative plasma exchange. A standard triple-drug immunosuppressive protocol was used post-operatively. Abs were analyzed by the complement dependent cytotoxicity (CDC) test against donor and panel B/T cells and by flow cytometry (FlowPRA tests detecting isolated HLA class I/II antigens). Abs against the donor's erythrocytes were analyzed using a standard direct agglutination test for immunoglobulin M (IgM) Abs and a Bio-Rad AHG gel card test detecting IgG Abs and C3d. RESULTS: Pre-transplant treatment reduced Ab titers against the donor's lymphocytes from 128 to 16 and against the donor's blood group A1 antigen from 256 to 0. The patient was emergently transplanted with a heart from a blood group incompatible donor (A1 secretor to O). No hyperacute rejection was seen. DRA were present against all mismatched HLA class I and class II antigens at the time of transplantation; two of these DRA Abs disappeared within the first year post-transplant (anti-B62 and anti-DR4), one showed weakened reactivity (anti-A24) and one is still strongly reactive (anti-DQ3). The donor-specific CDC cross-match is still positive (titers 2 to 8). The level of panel reactive antibodies (PRA) remained unchanged from 6 months on post-transplant. Rising anti-A1 blood group Abs preceded the second rejection and were adsorbed by two blood group specific immunoadsorptions (Glycosorb)-ABO) and remained at a low level. IgM anti-A1 blood group Abs disappeared at 1 yr post-transplant and IgG Abs are still reactive with blood group A1 erythrocytes but at low titers (1 to 2). CONCLUSIONS: The patient is clinically well 2 years after heart transplantation despite the constant persistence of donor reactive IgG Abs against blood group A1 and HLA-DQ antigens. The reactivity of DRA against other mismatched HLA antigens disappeared or weakened during the follow-up period.

Heart transplantation across the antibodies against HLA and ABO.

We have intentionally performed heart transplantation in a 5-year-old child, despite the most unfavourable risk factors for patient survival; the presence of high level of antibodies against donor's human leucocyte antigen (HLA) class I/II and blood group antigens. Pretransplant treatment by mycophenolate mofetil, prednisolone, tacrolimus, intravenous immunoglobulin, rituximab, protein-A immunoadsorption (IA) and plasma exchange reduced antibody titres against the donor's lymphocytes from 128 to 16 and against the donor's blood group antigen from 256 to 0. The patient was urgently transplanted with a heart from an ABO incompatible donor (A(1) to O). A standard triple-drug immunosuppressive protocol was used. No hyperacute rejection was seen. Antibodies against the donor's HLA antigens remained at a low level despite three acute rejections. Rising anti-A(1) blood group antibodies preceded the second rejection and were reduced by two blood group-specific IAs and remained at a low level. The patient is doing well despite the persistence of donor-reactive antibodies.

[Tricuspid valve stenosis--an serious complication to Port-a-cath]. / Trikuspidalisstenos--en allvarlig komplikation till Port-a-cath.

Tricuspid valve stenosis and occlusion of superior vena cava are severe complications to Port-a-cath. In a child with SLE, symptoms started to develop about five to seven years after Port-a-cath insertion and cyclophosphamid injections. The patient developed hepatomegaly with abdominal and venous distension. Open heart surgery was necessary to remove the catheter. At operation it was found that the catheter was placed adjacent and through the tricuspid valve. The valve was severely stenosed with thrombus formation. The catheter and thrombus were removed, commissurotomy and bicuspidization of the valve and chordeal replacement performed to achieve an acceptable functional result. The superior vena cava was repaired with a pericardial patch. Retrospective analyses of the echocardiograms and chest x-rays show that the catheter was nearly related to the tricuspid valve and with the tip in the right ventricle. In such circumstances it is recommended with early withdrawal of the catheter, and in patients with immunological disease the indwelling time should be considered and limited.