Raúl Abella

Early Initiation of Renal Replacement Therapy in Pediatric Heart Surgery Is Associated with Lower Mortality

Acute kidney injury (AKI) is frequent in the postoperative period of pediatric heart surgery and leads to significant morbidity and mortality. Renal replacement therapies (RRTs) are often used to treat AKI; however, these therapies have also been associated with higher mortality rates. Earlier initiation of RRT might improve outcomes. This study aims to investigate the relationship between the RRT and morbidity and mortality after pediatric heart surgery. We performed a single-center retrospective study of all children undergoing pediatric heart surgery between April 2010 and December 2012 at a tertiary children’s hospital. A total of 480 patients were included. Of those, 109 (23xa0%) were neonates and 126 patients (26xa0%) developed AKI within the first 72 postoperative hours. Patients who developed AKI had longer PICU admissions [12xa0days (4–37.75) vs. 4 (2–11); pxa0<xa00.001] and hospital length of stay [27 (11–53) vs. 14 (8–24) pxa0<xa00.001] and higher mortality [22/126 (17.5xa0%) vs. 13/354 (3.7xa0%); pxa0<xa00.001]. RRT techniques were used in 32 (6.6xa0%) patients [18/109 (16xa0%) neonates and 14/371 (3.8xa0%) infants and children; pxa0<xa00.01], with 25 (78xa0%) receiving peritoneal dialysis (PD) and 7 (22xa0%) continuous RRT (CRRT). Patients who received PD within the first 24 postoperative hours had lower mortality compared with those in whom PD was initiated later [4/16 (25xa0%) vs. 4/9 (44.4xa0%)]. Mortality among patients who received CRRT was 28.6xa0% (2/7). No deaths were reported in patients treated with CRRT within the first 24 postoperative hours. Postoperative AKI is associated with higher mortality in children undergoing cardiac surgery. Early initiation of RRT, both PD in neonates and CRRT in pediatric patients, might improve morbidity and mortality associated with AKI.

Fontan operation for patients with complex anatomy: the intra-atrial conduit technique.

The extracardiac conduit type of total cavopulmonary connection (TCPC) is the most common variation of the modified Fontan operation in current use. For patients with some forms of complex anatomy (eg, dextrocardia in situs solitus or asplenia syndrome), we have adopted a different technique: interposition of an intra-atrial conduit between the inferior vena cava (IVC) and the superior vena cava–right pulmonary artery (SVC-RPA) connection. We report our experience with six patients.

Impact of the implementation of an interdisciplinary infection control program to prevent surgical wound infection in pediatric heart surgery.

AbstractSurgical site infection (SSI) remains a major source of morbidity, mortality, and increased health care costs in children undergoing heart surgery. The aim of this study was to assess the effectiveness of an intervention program designed to reduce the high incidence of SSI observed at our center in pediatric patients. An interdisciplinary infection control program including pre-, intra-, and postoperative measures was introduced for children undergoing heart surgery with cardiopulmonary bypass. We conducted a quasi-experimental interventional study comparing a pre-intervention cohort (June 2009 to March 2010) and a post-intervention cohort (July 2011 to July 2012). A significant drop in SSI incidence from 10.9xa0% (95xa0% CI 4.7–18.8) to 1.92xa0% (95xa0% CI 0.4–5.52) was observed. Variables significantly associated with infection risk were median age (14xa0days in infected vs 2.3xa0years in non-infected patients; pu2009<u20090.01), hospitalization unit (10.3xa0% SSI cumulative incidence in the neonatal intensive care unit vs 0 cases in the pediatric intensive care unit; pu2009<u20090.01), and median preoperative hospital stay (14xa0days in infected vs 1xa0day in non-infected patients; pu2009=u20090.03).n Conclusions: The implementation of a new intervention program was associated with an 82xa0% (95xa0% CI 34–94) reduction in SSI incidence in children undergoing heart surgery at our center. What is known:• Surgical site infection (SSI) is associated with significant morbidity and mortality following pediatric cardiac surgery.• Younger patients and longer cardiopulmonary bypass times are associated with higher SSI rates.What is New:• Comprehensive infection control program including preoperative, intraoperative and postoperative nonpharmacologic measures is a key factor for the prevention of SSI.• A significant reduction in SSI rates can be achieve despite a narrower-spectrum antibiotic usage.

Graves’ Disease TSHR-Stimulating Antibodies (TSAbs) Induce the Activation of Immature Thymocytes: A Clue to the Riddle of TSAbs Generation?

Graves’ disease (GD) is an autoimmune thyroid disease defined by the production of stimulating autoantibodies to the thyroid-stimulating hormone receptor (TSHR) (TSAbs) that induce a sustained state of hyperthyroidism in patients. We previously demonstrated that TSHR, the target of this autoimmune response, is also a key susceptibility gene for GD, probably acting through thymic-dependent central tolerance. We also showed that TSHR is, unexpectedly, expressed in thymocytes. In this report, we confirm the expression of TSHR in thymocytes by protein immunoblotting and quantitative PCR, and show that expression is confined to maturing thymocytes. Using functional assays, we show that thymic TSHR is functional and that TSAbs can stimulate thymocytes through this receptor. This new activity of TSAbs on thymocytes may: 1) explain GD-associated thymic enlargement (hyperplasia), and 2) suggest the provocative hypothesis that the continuous stimulation of thymocytes by TSAbs could lead to a vicious cycle of iterative improvement of the affinity and stimulating capability of initially low-affinity antibacterial (e.g., Yersinia) Abs cross-reactive with TSHR, eventually leading to TSAbs. This may help to fill one of the gaps in our present understanding of unusual characteristics of TSAbs.

Pulmonary Interstitial Glycogenosis A Reversible Underlying Condition Associated With D-Transposition of the Great Arteries and Severe Persistent Pulmonary Hypertension

Transposition of the great arteries with intact ventricular septum and persistent pulmonary hypertension (TGA-IVS PPHN) is a rare association with a poor prognosis. We report the case of a term newborn with TGA-IVS PPHN successfully managed with perioperative extracorporeal membrane oxygenation (ECMO) and aggressive pulmonary vasodilation therapy that underwent successful arterial switch procedure. A lung biopsy obtained during the surgical procedure showed pulmonary interstitial glycogenosis, a reversible condition. Concerns over left ventricle deconditioning after ECMO could be minimized with appropriate management and monitoring of the ductus arteriosus and appropriate timing of surgery.

Heart transplantation in pediatric patients with pulmonary hypertension.

Patients with congenital heart disease may have pulmonary hypertension secondary to increased pulmonary flow, persistent hypoxemia, or elevated left-side filling pressures. Persistently elevated pulmonary pressure causes pulmonary vasculature remodeling and pulmonary hypertension refractory to vasodilator therapy. Previous reports have described the anatomic-pathologic changes in pulmonary vasculature and their importance. Pulmonary hypertension may be a contraindication for heart transplantation. However, it is difficult to determine the pulmonary resistance value that should be used to contraindicate heart transplantation. Recommendations for pediatric patients are based on experience with adults, and the latest guidelines establish an upper limit of 6 UW/m after the administration of pulmonary vasodilator therapy. Nevertheless, some authors defend the possibility of heart transplantation at higher values. From December 2008 to December 2013, we performed 22 heart transplantations in pediatric patients, among them, 5 patients with severe pulmonary hypertension. The characteristics of these patients are described in the Table. All patients underwent catheterization prior to transplantation, except for 1 patient whose pulmonary pressure was estimated by echocardiography. Pulmonary resistances were calculated at baseline and after the administration of pulmonary vasodilator therapy (nitric oxide). Patient 4 was on the transplantation waiting list for 2 years, but had considerable clinical deterioration with the development of severe pulmonary hypertension (Table); hence, a decision was made to implant a left ventricular assist device and administer pulmonary vasodilator therapy. One month later, the catheterization was repeated and pulmonary resistances had dropped to 3.5 UW/m and, therefore, the patient was put back on the transplantation waiting list. One patient died in the acute phase of the postoperative period due to humoral rejection. All other patients are alive and progressing well. Two patients (40%) required mechanical assistance, 1 due to humoral rejection and the other due to right ventricular dysfunction. All had moderate-to-severe right ventricular dysfunction and required inotropic support and pulmonary vasodilator therapy. In the patients without pulmonary hypertension, right ventricular dysfunction was observed in 9 of 17 (53%; P < .05). Pulmonary vasodilator therapy was maintained at discharge (oral sildenafil), but all patients discontinued the drug during follow-up. Pulmonary biopsies were obtained in 2 patients (Figure) and showed the entire spectrum of vascular lesions characteristic of pulmonary hypertension, with involvement of preacinar and intraacinar arterial vessels, such as plexiform vasculopathy. A venous condition was also observed in the form of hypertrophy. In 1 patient (Figure A), there was a predominance of medial hypertrophy changes in preacinar vessels and plexiform vasculopathy. In the other patient (Figure B), these changes were less serious, but greater intimal thickening was observed, as well as venous involvement with lymph vessel dilation. Comparison of these patients with those without pulmonary hypertension showed no statistically significant differences in survival: 80% of patients with pulmonary hypertension survived compared with 88% of patients without hypertension, with a mean follow-up of 27 (10-62) and 29 (7-60) months, respectively (P > .5). We did observe a higher incidence of cellular (80% vs 24%; P = .02) and humoral (80% vs 12%; P < .01) rejection in patients with pulmonary hypertension, probably due to the greater complexity in this subgroup: 80% of patients with pulmonary hypertension compared with 29% in those without pulmonary hypertension underwent more than 1 cardiac surgery prior to transplantation, including placement of a ventricular assist device (P = .04). Only 2 patients, 1 in each group, had developed antihuman leukocyte antibodies (HLA) before transplantation. In conclusion, it is difficult to establish a value of pulmonary resistance that could be used to contraindicate heart transplantation. Likewise, when referring to pulmonary resistances, the term irreversible should be used with caution because these resistances Rev Esp Cardiol. 2014;67(8):669–679

Caracterización y factores de riesgo de dilatación aórtica en pacientes pediátricos con válvula aórtica bicúspide

INTRODUCTION AND OBJECTIVESnDilatation of the ascending aorta associated with bicuspid aortic valve is a major cause of morbidity and mortality in adults. The main objective was to recognize the aortic involvement in children, its characteristics and risk factors.nnnMETHODSnAortic measures of all pediatric patients with bicuspid aortic valve followed in a tertiary pediatric hospital between 1997 and 2015 were retrospectively taken. Patients with syndromes associated with aortic dilatation were excluded (n=17).nnnRESULTSnTwo hundred and six patients were included, 67.9% males. The commonest opening pattern was horizontal: 137 (66.7%). Half of the patients (101) had a history of surgical aortic coarctation, 46 (22.3%) had≥moderate aortic valve stenosis and 13 (6%) had≥moderate aortic insufficiency. Mean follow-up time was 6.1 (4.9) years; diagnosis of aortic dilatation was made during the first year of follow-up. Progression of the dilatation of the ascending aorta was noted in 17.1%, and of the aortic root in 2.5%. More than one-third (80/206) had aortic dilatation (z-score>2). The ascending aorta was exclusively affected in 70/80 patients, with sparing of the aortic root. In the multivariate analysis, patients with dilatation of the ascending aorta were associated with absence of coarctation (P=.001) and vertical opening pattern (P=.007).nnnCONCLUSIONSnPediatric patients with bicuspid aortic valve warrant medical follow-up for the frequent association with valve impairment and/or dilatation of the ascending aorta.

Correction of Congenital Cardiac Defects With CorMatrix Extracellular Matrix in Pediatric Patients: Is It Really Safe?

Actualmente las cardiopatı́as congénitas se corrigen en más de la mitad de los casos durante los primeros 12 meses de vida, con una mejora de la mortalidad respecto a décadas pasadas. Por el contrario, algunos pacientes siguen requiriendo varias intervenciones debido al uso de ciertos materiales durante la reparación. Se están evaluando nuevos productos con la intención de reducir el número de intervenciones. Uno de los más utilizados es la matriz extracelular, y el CorMatrix (CorMatrix Cardiovascular, Inc.; Alpharetta, Georgia, Estados Unidos) es una de las que se tiene mayor experiencia tanto clı́nica como experimental. Como grupo, empezamos a utilizar dicha matriz en un total de 30 pacientes desde octubre de 2010 a junio de 2014 (tabla), realizando un seguimiento de estos pacientes mediante ecocardiografı́as seriadas. La media de edad de los pacientes en el momento de la cirugı́a era de 6 meses (1 mes-3,8 años), con una media de peso de 7,5 (3,5-14,5) kg. No hubo pérdidas en el seguimiento, que tuvo una media de 268 (194,5-305,8) dı́as.

Echocardiography in the Assessment of Left Atrial Pressure After Pediatric Heart Surgery A Comparison Study With Measurements Obtained From Left Atrial Catheter

Background: Correlation between ventricular end-diastolic pressure and pulsed Doppler and tissue Doppler–derived E/e’ ratio has been widely reported in adults but scarcely studied in children with congenital heart diseases. This ratio is defined as the relationship between diastolic transmitral flow velocity (cm/s; E) and myocardial diastolic relaxation velocity (cm/s; e’) in the lateral aspect of the mitral annulus. Our main objective was to ascertain whether a correlation existed between direct measurement of left atrial pressure and echocardiographic E/e’ ratio in children after heart surgery. Methods: Prospective study including 27 consecutive children after pediatric heart surgery. Data were analyzed according to whether they were obtained within the first 72 hours following surgery or later on. Sensitivity, specificity, positive and negative predictive values, and areas under the receiver–operating characteristics curve of E/e’ ratio in detection of left atrial pressure values ≥13 mm Hg were evaluated. Results: Forty-eight studies were conducted in 27 patients. Thirty-two studies were performed during the first 72 hours after heart surgery and 16 beyond the third day. Median patient age was 0.82 years (5 days-16 years). Median left atrial pressure values and E/e’ measurements of the whole cohort (N = 48) were 12.0 and 10.2, respectively. Intraclass correlation index between left atrial pressure values and echocardiographic E/e’ ratio was 0.35, 0.25 for studies performed within 72 hours, but 0.78 (P < .01) for those performed later. There was also a high positive predictive value, since in 13 (87%) of 15 studies with an E/e’ ratio ≥13, the left atrial pressure was ≥13 mm Hg. Conclusion: While echocardiographic E/e’ ratio did not show a good correlation with left atrial pressure in the immediate postoperative period, the positive predictive value may suffice to aid clinicians in predicting elevated pressures.

Right corkscrew cervical aortic arch.

Figure 1: CT image shows the thoracic aorta and supra-aortic trunks seen from anterior (a) and left (b) point of view. The CT measurements are 16 mm for the ascending aorta and 5 mm for the aortic arch and descending thoracic aorta. AA: ascending aorta; AoA: aortic arch; IA: innominate artery; LSA: left subclavian artery; LVA: left vertebral artery; RSA: right subclavian artery. Figure 2: MRI shows very tortuous great vessels, right aortic cervical arch, with right carotid and subclavian right arising from the innominate artery. The left carotid artery is very hypoplastic and arises from a common trunk with ipsilateral subclavian. Both are nourished by collateral circulation. In the cerebral circulation, the left middle cerebral artery is fed through the left posterior communicating in the Willis polygon. AA: ascending aorta; AoA: aortic arch; IA: innominate artery; LSA: left subclavian artery; LVA: left vertebral artery; WP: Willis polygon.