ABSTRACT
Introducción: La enfermedad por el nuevo coronavirus provocó una pandemia con impacto en la salud infantil que hizo patente la relación entre un estado de inflamación, hipercoagulabilidad y trombosis vascular como génesis de la insuficiencia respiratoria aguda. Objetivo: Describir la epidemiología de la trombosis vascular en pediatría y resumir las principales evidencias disponibles relacionadas con la interacción entre la hiperinflamación, disregulación inmunológica, hipercoagulabilidad y trombosis. Métodos: Entre diciembre 2019 y junio de 2021, se realizó una revisión ordenada de las bases de datos médicas PubMed, y Google Scholar, en las que se emplearon los términos de los títulos (MeSH): "SARS-CoV-2 and Covid-19"; "coronavirus" and "infección"; "sepsis" and "Covid-19" and "Síndrome inflamatorio multisistémico en niños" and "MIS-C and "PIMS-TS". Análisis y síntesis de la información: La trombosis vascular en pediatría se presenta entre 1,2 y 26 %, generado por procesos inflamatorios que conducen a una endotelítis con alteraciones de las estructuras microvasculares y la formación de trombos. Existen factores de riesgos como edad≥ 12 años, ventilación mecánica, abordaje venoso profundo, presencia de síndrome inflamatorio multisistémico, obesidad y cáncer. El diagnóstico se sustenta con análisis específicos en especial el dímero D, ultrasonidos con dopplers y tomografías. El tratamiento con anticoagulante no se ha unificado y dependerá de los protocolos indicados en cada país. Conclusiones: La trombosis vascular en pediatría, aunque infrecuente, debe tenerse presente para detectar su presencia en pacientes graves con factores de riesgo y actuar en consecuencia de acuerdo con los protocolos establecidos.
Introduction: The disease by the new coronavirus caused a pandemic with an impact on children's health, which made clear the relationship between a state of inflammation, hypercoagulability and vascular thrombosis as the genesis of acute respiratory failure. Objective: To describe the epidemiology of vascular thrombosis in pediatrics and to summarize the main available evidence related to the interaction between hyperinflammation, immune dysregulation, hypercoagulability and thrombosis. Methods: Between December 2019 and June 2021, an orderly review of the medical databases PubMed and Google Scholar was carried out, in which the terms of the titles (MeSH) were used: "SARS-CoV-2 and Covid-19"; "coronavirus" and "infection"; "sepsis" and "Covid-19" and "Multisystem inflammatory syndrome in children" and "MIS-C and "PIMS-TS". Analysis and synthesis of information: Vascular thrombosis in pediatrics occurs between 1.2 and 26%, generated by inflammatory processes that lead to endothelitis with alterations of microvascular structures and thrombus formation. There are risk factors such as age≥ 12 years, mechanical ventilation, deep venous approach, presence of multisystem inflammatory syndrome, obesity and cancer. The diagnosis is supported by specific analyzes, especially the D-dimer, ultrasound with Dopplers and tomography. Anticoagulant treatment has not been unified and will depend on the protocols indicated in each country. Conclusions: Vascular thrombosis in pediatrics, although infrequent, should be kept in mind to detect its presence in severe patients with risk factors and act accordingly with established protocols.
ABSTRACT
The studies about factors influencing the retroprostheic membrane formation, one of major complications after keratoprosthesis implantation, and about histological characteristics of the retroprosthetic membrane were performed. The methods to inhibit formation and proliferation of membrane were also tried. Formation of the membrane according to corneal trephination size and the effects of lens removal to membrane formation were studied. The influence by the design of keratoprosthesis was also studied. Corticosteroid and SIMP (synthetic inhibitor of metalloproteinase) were applied topically to see the inhibitory effects of drugs to membrane. To evaluate the postoperative intraocular inflammation. Interleukin-1beta was assessed in the aqueous humor at postoperative 3 weeks. Regardless of trephination size, all trephination sites were replaced with opaque fibrous membranes. Histologically, in small trephination group (under 6mm) the membrane was regeneration of cornea showing corneal stromal fibroblast migration and proliferation and mature collagen. In large trephination group (over 7mm), the periphery of the membrane was compatible with corneal regeneration, but central portion was filled with granulation tissue. The removal of lens didn`t influenced the formation of membrane formation. In disc type keratoprosthesis implantation group, all the implants were extruded within 1 month due to retroprosthetic membrane formation. In cylinder type keratoprosthesis implantation group, the physical barrier of cylinder stopped the retroprosthetic membrane proliferation and spared the posterior surface of optic portion. The implants were not extruded for average 10 weeks. Corticosteroid and SIMP showed the effects of decreasing mature collagen formation in the membrane. The level of Interleukin-1beta at postoperative 3 weeks showed no difference according to different drugs and the highest level was checked in cylinder type keratoprosthesis implantation group.