Síndrome de hipoplasia de corazón izquierdo: experiencia de 10 años de un programa de etapificación quirúrgica / Hypoplastic left heart syndrome: 10 year experience with staged surgical management

Resumen El síndrome de hipoplasia de corazón izquierdo (SHCI) es una cardiopatía congénita con letalidad superior al 95%. La etapificación quirúrgica es la principal vía de tratamiento, y se inicia con la operación de Norwood; la sobrevida a largo plazo de los pacientes tratados es desconocida en nuestro medio. Objetivos 1) Revisar nuestra experiencia en el manejo de todos los pacientes con SHCI evaluados entre enero 2000 y junio 2010. 2) Identificar factores de riesgo de mortalidad quirúrgica. Pacientes y método Estudio retrospectivo de una única institución con una cohorte de pacientes con SHCI. Se revisan antecedentes clínicos, quirúrgicos, y registros de seguimiento. Resultados Se evaluaron 76 pacientes con SHCI; 9/76 tenían comunicación interauricular (CIA) restrictiva, y 8/76, aorta ascendente de < 2 mm; 65/76 fueron tratados: 77% tuvieron operación de Norwood con conducto entre ventrículo derecho y ramas pulmonares como fuente de flujo pulmonar, 17% Norwood con shunt de Blalock-Taussig, y 6% otra cirugía. La mortalidad en la primera etapa quirúrgica fue del 23%, y en operación de Norwood, del 21,3%. En el período 2000-2005 la mortalidad en la primera etapa quirúrgica fue del 36%, y entre 2005-2010, del 15% (p = 0,05). La sobrevida global fue del 64% a un año y del 57% a 5 años. Por análisis multivariado fueron factores de riesgo para mortalidad la presencia de aorta ascendente diminuta y CIA restrictiva. Conclusiones Nuestros resultados inmediatos y a largo plazo en la etapificación quirúrgica de SHCI son similares a la experiencia de grandes centros. Hay una mejoría en mortalidad operatoria en la segunda mitad de la serie. Se identifican factores de riesgo de mortalidad.

Abstract Hypoplastic left heart syndrome (HLHS) is a lethal congenital heart disease in 95% of non-treated patients. Surgical staging is the main form of treatment, consisting of a 3-stage approach, beginning with the Norwood operation. Long term survival of treated patients is unknown in our country. Objectives 1) To review our experience in the management of all patients seen with HLHS between January 2000 and June 2012. 2) Identify risk factors for mortality. Patients and method Retrospective analysis of a single institution experience with a cohort of patients with HLHS. Clinical, surgical, and follow-up records were reviewed. Results Of the 76 patients with HLHS, 9 had a restrictive atrial septal defect (ASD), and 8 had an ascending aorta ≤ 2 mm. Of the 65 out of 76 patients that were treated, 77% had a Norwood operation with pulmonary blood flow supplied by a right ventricle to pulmonary artery conduit, 17% had a Norwood with a Blalock-Taussig shunt, and 6% other surgical procedure. Surgical mortality at the first stage was 23%, and for Norwood operation 21.3%. For the period between 2000-2005, surgical mortality at the first stage was 36%, and between 2005-2010, 15% (P = .05). Actuarial survival was 64% at one year, and 57% at 5 years. Using a multivariate analysis, a restrictive ASD and a diminutive aorta were high risk factors for mortality. Conclusions Our immediate and long term outcome for staged surgical management of HLHS is similar to that reported by large centres. There is an improvement in surgical mortality in the second half of our experience. Risk factors for mortality are also identified.

Role of reactive oxygen species in bradykinin-induced proliferation of vascular smooth muscle cells

In addition to the induction of cell proliferation and migration, bradykinin (BK) can increase c-fos mRNA expression, activate ERK 1/2 and generate reactive oxygen species (ROS) in vascular smooth muscle cells (VSMC). It is not known, however, whether BK can induce cellular proliferation and extracellular matrix production via redox-sensitive signaling pathways. We investigated the role(s) of ROS in proliferation, migration and collagen synthesis induced by BK in VSMC derived from Sprague Dawley rat aorta. BK (10 nM) increased VSMC proliferation by 30 % (n=5); this proliferation was inhibited by the antioxidants N-acetylcysteine (20 mM) and a-lipoic acid (LA, 250 mM). In addition, BK induced an increase in cell migration and in collagen levels that were blocked by LA. ROS production induced by BK (n=10) was significantly inhibited by bisindolylmaleimide (4mM) and by PD98059 (40mM). These results suggest that: 1) ROS participate in the mechanism(s) used by bradykinin to induce cellular proliferation; 2) bradykinin induces ROS generation through a pathway that involves the kinases PKC and MEK; and 3) ROS participate in the pathways mediating cell migration and the production of collagen as a response to treatment with bradykinin. To our knowledge, this is the first report describing mechanisms to explain the participation of ROS in the cellular proliferation and extracellular matrix pathway regulated by BK.