Human cornea conservation in coconut water solution / Conservação de córneas humanas em solução de água de coco

ABSTRACT Purpose: The aim of this study was to evaluate the physical and chemical characteristics of coconut water and to analyze the use of coconut water solution for the conservation of human corneas. Methods: This was an experimental and controlled study performed at the Eye Bank of the General Hospital of Fortaleza. The coconut water-based solution was prepared at the Goat Seed Technology Laboratory of the Department of Veterinary Medicine of the State University of Ceará. Discarded corneas from the Eye Bank were divided into two groups for sequential experiments: G1, coconut water-based solution (experimental group), and G2, conservative treatment with OPTISOL GS® (control group). The osmolality of corneas in G1 was analyzed sequentially at 275, 300, 325, 345, 365, and 400 mOsm/L. The viability of the corneas was determined by specular microscopy and biomicroscopy on the first, third, and seventh days. Results: Corneas preserved in a solution of 365 and 345 mOsm/L had a transparency of 8 mm until the third day and had diffuse edema in the periphery, central folds, and partial epithelium loss until the seventh day. The 365-mOsm/L solution was associated with the worst results during follow-up. Corneas placed in Optisol-GS retained their original aspects. Conclusions: Coconut water-based preservative partially maintained corneal transparency and epithelial integrity, especially during the first three days of follow-up. The coconut water-based solutions used were not effective for use as preservatives in a human eye bank.(AU)

RESUMO Objetivos: As características físico-químicas e o baixo custo da água de coco foram fundamentais para o este estudo. Analisar o uso de solução a base de água de coco como meio de conservação de córneas humanas em banco de olhos. Métodos: Estudo experimental e controlado realizado no Banco de Olhos do Hospital Geral de Fortaleza. Utilizou-se solução à base de água de coco preparada no laboratório de Tecnologia de Sêmen de Caprinos do Departamento de Medicina Veterinária da Universidade Estadual do Ceará. Foram usadas córneas de descartes divididas em dois grupos: G1 (Conservante com água de coco) - grupo experimental e G2 (grupo Conservante com OPTISOL GS®) grupo controle, em experimentos sequenciais. A osmolaridade do G1 foi analisada sequencialmente com 275, 300, 325, 345, 365 e 400 mOsm/L. A viabilidade das córneas foram realizadas por microscopia especular e biomicroscopia nos 1º, 3º e 7º dias. Resultados: As córneas em solução de 365 e 345 mOsm/L apresentavam transparência nos 8mm centrais até o 3º dia, com edema em toda periferia, dobras centrais e edema 2+, com perda parcial do epitélio até 7º dia, sendo o de maior osmolaridade com melhor transparência durante o seguimento. Grupo com 275, 300 e 400 mOsm/L, córnea opaca, edema difuso, perda total do epitélio no 3º dia. As córneas em Optisol mantiveram seus aspectos. Conclusões: O conservante à base de água de coco manteve em parte a transparência corneana e a integridade epitelial, especialmente nos primeiros 3 dias de seguimento. A solução conservante com água de coco nas formulações utilizadas não se mostrou eficaz para o uso em banco de olhos humanos.(AU)

Trasplante cardíaco con donantes cadavéricos: de la investigación a la práctica clínica / Heart Transplantation Using Donors after Circulatory Death: From Research to Clinical Practice

Los donantes cadavéricos para trasplante cardíaco se abandonaron en la década de los setenta con el advenimiento de la ley de muerte cerebral (cadáveres con corazón latiendo), en los cuales el corazón se halla latiendo y perfundido hasta último momento previo al explante. La escasez de donantes ha reavivado el interés en la investigación en animales y clínica con el fin de utilizar donantes cadavéricos para trasplante cardíaco, intentando optimizar la función cardíaca luego del período de deprivación de oxígeno producido por la hipotensión muy pronunciada y la detención circulatoria posterior. Se presenta la experiencia inicial de trasplante cardíaco con donantes cadavéricos en nuestra institución. El Papworth Hospital ha realizado una investigación clínica exitosa, efectuando diez trasplantes cardíacos con donantes cadavéricos, sin mortalidad. Se eligieron recipientes de riesgo bajo con consentimiento previo. Los donantes cadavéricos fueron, en su mayoría, reperfundidos con el uso de dispositivo de circulación extracorpórea y, luego de ser destetados del apoyo circulatorio, en todos los casos el corazón fue explantado y conectado a la máquina de perfusión para ser trasladado y a la vez evaluado en su función para proceder al implante. En conclusión, esta técnica se podría utilizar para trasplante cardíaco con buenos resultados.

Donation after circulatory death for heart transplantation was abandoned in the 1970s with the advent of the brain death law (donation after brain death), where the donor heart is beating and perfused up to the moment prior to organ retrieval. Shortage of donors has renewed the interest in animal and clinical research of donors after circulatory death for heart transplantation, aiming at optimizing heart function after the period of oxygen deprivation caused by severe hypotension and subsequent circulatory arrest. This study presents the initial experience with donation after circulatory death for heart transplantation at our institution. Papworth Hospital has performed a successful clinical investigation in which ten cardiac transplants were performed with hearts from donation after circulatory death, without mortality. Low risk recipients who had previously signed their consent were chosen. Most hearts from donation after circulatory death were reperfused with an extracorporeal circulation device, and following weaning from the circulatory support the heart was harvested and connected to the perfusion machine for transportation and simultaneous assessment of function before implantation. In conclusion, this technique could be used for cardiac transplantation with satisfactory outcomes.