Comprehensive Assessment of Indocyanine Green Usage: One Tracer, Multiple Urological Applications.

The intraoperative use of fluorescent tracers and matching cameras can empower urologists' ability to recognize critical anatomical and functional features. Indocyanine green is the most extensively used near-infrared fluorescent tracer. It has been widely applied due to its ability to illuminate vascular and lymphatic anatomies. A plurality of fluorescence cameras are available allowing the connection of this technology with many surgical approaches, including robotic surgery. Although large comparative validation studies are lacking, numerous studies support the role of fluorescence guidance in urology.

Derrame pleural unilateral tras perforación vascular por catéter venoso central de inserción periférica: utilidad del verde de indocianina en el diagnóstico / Unilateral pleural effusion caused by vessel perforation due to peripherally inserted central catheter: Indocyanine green as a diagnostic tool

Varón de 44 años con desnutrición calórico-proteica grave en el contexto de una estenosis pilórica benigna, a quien se decidió colocar un catéter central de inserción periférica (CCIP) para tratamiento con nutrición parenteral. Al quinto día de la inserción del catéter, presentó un derrame pleural derecho masivo de color blanco e insuficiencia respiratoria tras la realización de una endoscopia digestiva alta para el tratamiento de la estenosis pilórica. Ante la sospecha inicial de quilotórax el paciente ingresó en la Unidad de Reanimación. Se administró verde de indocianina a través del CCIP, obteniendo a los 30 min una coloración verdosa del contenido del derrame pleural; este resultado nos hizo sospechar que el derrame pleural era secundario a una perforación vascular por el CCIP con extravasación de la nutrición parenteral al espacio pleural. Se realizó una tomografía computarizada toracoabdominal, que confirmó la existencia de una perforación a nivel de la vena innominada. La colocación de un CCIP puede asociarse a complicaciones graves, como la perforación de una vena central, por tanto, la correcta posición de un catéter central debe ser siempre comprobada. La prueba diagnóstica de elección de perforación vascular a nivel central es la tomografía computarizada con contraste; sin embargo, ante la existencia de derrame pleural en este contexto, es posible emplear un colorante que, administrado de forma intravenosa, oriente su diagnóstico in situ. En este caso se empleó el verde de indocianina con este objetivo (AU)

A peripherally inserted central catheter (PICC) was inserted into a 44-year-old man to provide parenteral nutrition in a protein-calorie malnutrition secondary to a benign pyloric stenosis. On the fifth day while monitoring the catheter, the patient presented with a massive whitish pleural effusion after undergoing gastric endoscopy in order to treat pyloric stenosis. Chylothorax was initially suspected, and the patient was admitted to a recovery unit. Indocyanine green was administered through the PICC, obtaining a greenish discoloration in the pleural effusion 30 min later. This led to the diagnosis of a pleural effusion caused by a vessel perforation due to the PICC, leading to parenteral nutrition extravasation. Thoraco-abdominal computed tomography was performed, which confirmed an innominate vein perforation due to the PICC. PICC insertion may be associated with severe complications, such as central vessel perforation, and therefore the correct position of a central catheter should be always checked. Intravenous computed tomography contrast is the gold standard for central vascular perforation diagnosis. However if a pleural effusion occurs in this context, it is possible to use a dye, which administered intravenously can lead us to the correct diagnosis in situ. Indocyanine green was used for this purpose in this case (AU)

Intuitiveness, quality and utility of intraoperative fluorescence videoangiography: Australian Neurosurgical Experience.

INTRODUCTION: The authors have undertaken a study of their intraoperative experience with indocyanine green fluorescence videoangiography (ICGFV). In particular, the intuitiveness, image quality and clinical utility of this technology have been assessed. METHODS: The records of forty-six consecutive craniotomies utilising ICGFV have been retrospectively reviewed: There were 27 aneurysms, 2 extracranial-intracranial (EC-IC) bypasses, 5 arteriovenous malformations (AVM), 1 dural arteriovenous fistula (DAVF), 3 cavernomas, 5 meningiomas, and 3 gliomas. ICGFV was used in 5 awake-craniotomy patients. ICGFV was performed using a Leica OH4 surgical microscope with integrated near-infrared camera and ICG-PULSION. RESULTS: All attempts of intraoperative ICGFV were intuitive. Image quality and resolution were excellent. Arterial and venous phases were comparable to digital subtraction angiography (DSA) but field of view was relatively limited. In 12 operations (26%) the surgeon was substantially benefited from ICGFV findings. In 22 operations (48%), ICGFV was useful but did not influence surgical management. ICGFV was of no benefit in 11 operations (24%) and was misleading in 1 (2%). In this series, ICGFV was of benefit to 1 of 11 (9%) patients with an intracranial neoplasm or cavernoma. CONCLUSIONS: ICGFV is safe, intuitive and provides neurosurgeons with high quality, valuable, real-time imaging of cerebrovascular anatomy. It can assist in intraoperative surgical management and/or stroke prevention particularly during aneurysm clipping, EC-IC bypass and AVM/DAVF surgery.

Emission and absorption properties of indocyanine green in Intralipid solution.

Emission and absorption properties of indocyanine green (ICG) in Intralipid solution have been investigated. The study is focused on relatively low ICG concentration at a range of 0 to 20 microM. A diffusion model was used to analyze the emission properties of ICG solution at different concentrations. In the low-concentration region, the emission strength increases with the concentration of ICG, while in the high-concentration region, the emission decreases with the concentration. In general, a maximum of emission strength exists and its position (concentration) depends on the wavelength of the excitation light, the distance between the source and the detector, and the sample geometry and size. A so-called "inner-cell-effect" and re-absorption of emission photons are found to contribute to the decay of emission strength. Also, in the concentration range of 0 to 2 microM, ICG solution always has a higher absorption coefficient at wavelength 830 nm than that at 660 nm, which is quite different from the ICG in water case.

[Indocyanine Green Reference Standard (Control 901) of National Institute of Hygienic Sciences].

The raw material of indocyanine green was examined for the preparation of the "Indocyanine green Reference Standard (Control 901)". Analytical data obtained were as follows: ultraviolet and visible spectrum, lambda max = 785, 394, 216 nm; absorbance, E1cm(1%) (785 nm) = 3239; infrared spectrum, same as Indocyanine Green USP Reference Standard; sodium iodide, 4.1%; thin-layer chromatography, no impurities were detected until 100 micrograms; high-performance liquid chromatography, 4 impurities were detected; loss on drying, 1.8%; assay, 103.4% against USP Reference Standard. Based on the above results, this raw material was authorized to be the Reference Standard of the National Institute of Hygienic Sciences.

Cardiac output measurement by indicator dilution.

The measurement of cardiac output by the indicator dilution method is reviewed. Theoretical and practical problems relating to the direct and indirect Fick methods and the continuous and bolus injection methods are considered in detail. Choice of indicator is also discussed. Problems remain with all of these methods, but reasonable accuracy and consistency may be achieved if attention is paid to detail.