Extracorporeal membrane oxygenation (ECMO) plays an important role in the coronavirus disease 2019 (COVID‐19) pandemic. Management of thrombi in ECMO is generally an important issue; especially in ECMO for COVID‐19 patients who are prone to thrombus formation, the thrombus formation in oxygenators is an unresolved issue, and it is very difficult to deal with. To prevent thromboembolic complications, it is necessary to develop a method for early thrombus detection. We developed a novel method for detailed real‐time observation of thrombi formed in oxygenators using indocyanine green (ICG) fluorescence imaging. The purpose of this study was to verify the efficacy of this novel method through animal experiments. The experiments were performed three times using three pigs equipped with veno‐arterial ECMO comprising a centrifugal pump (CAPIOX SL) and an oxygenator (QUADROX). To create thrombogenic conditions, the pump flow rate was set at 1 L/min without anticoagulation. The diluted ICG (0.025 mg/mL) was intravenously administered at a dose of 10 mL once an hour. A single dose of ICG was 0.25mg. The oxygenator was observed with both an optical detector (PDE‐neo) and the naked eye every hour after measurement initiation for a total of 8 hours. With this dose of ICG, we could observe it by fluorescence imaging for about 15 minutes. Under ICG imaging, the inside of the oxygenator was observed as a white area. A black dot suspected to be the thrombus appeared 6‐8 hours after measurement initiation. The thrombus and the black dot on ICG imaging were finely matched in terms of morphology. Thus, we succeeded in real‐time thrombus detection in an oxygenator using ICG imaging. The combined use of ICG imaging and conventional routine screening tests could compensate for each other's weaknesses and significantly improve the safety of ECMO.
Background Antithrombogenicity of extracorporeal membrane oxygenation (ECMO) devices, particularly oxygenators, is a current problem, with numerous studies and developments underway. However, there has been limited progress in developing methods to accurately compare the antithrombogenicity of oxygenators. Animal experiments are commonly conducted to evaluate the antithrombogenicity of devices; however, it is challenging to maintain a steady experimental environment. We propose an innovative experimental animal model to evaluate different devices in a constant experimental environment in real‐time. Methods This model uses two venous–arterial ECMO circuits attached to one animal (one by jugular vein and carotid artery, one by femoral vein and artery) and real‐time assessment of thrombus formation in the oxygenator by indocyanine green (ICG) fluorescence imaging. Comparison studies were conducted using three pigs: one to compare different oxygenators (MERA vs. CAPIOX) (Case 1), and two to compare antithrombotic properties of the oxygenator (QUADROX) when used under different hydrodynamic conditions (continuous flow vs. pulsatile flow) (Cases 2 and 3). Results Thrombi, visualized using ICG imaging, appeared as black dots on a white background in each oxygenator. In Case 1, differences in the site of thrombus formation and rate of thrombus growth were observed in real‐time in two oxygenators. In Case 2 and 3, the thrombus region was smaller in pulsatile than in continuous conditions. Conclusions We devised an innovative experimental animal model for comparison of antithrombogenicity in ECMO circuits. This model enabled simultaneous evaluation of two different ECMO circuits under the same biological conditions and reduced the number of sacrificed experimental animals.
Objective Saphenous vein grafts (SVGs) are widely used as bypass conduits in coronary artery bypass grafting. Compared with the conventional technique, the “no-touch” technique, wherein the saphenous veins are harvested with the surrounding tissue, may improve SVG patency; however, there are concerns regarding wound complications. To address this issue, we describe our novel no-touch technique with separate skin incisions using a long-shafted ultrasonic scalpel and report the clinical outcomes. Methods We enrolled 66 male patients who underwent isolated coronary artery bypass grafting between April 2016 and April 2021. There were 30 and 36 patients treated using our no-touch technique and the conventional technique, respectively. The participants underwent coronary angiography before discharge and were followed clinically. SVG samples were taken for pathological examination. Results SVGs harvested using our no-touch technique displayed preservation of the vessel wall structure and surrounding tissues. Our no-touch technique demonstrated no inferiority in patency compared with the conventional technique, and there was no SVG occlusion in the no-touch group. The frequency of leg wound complications was higher in the no-touch group than the conventional group, but no surgical site infections and severe complications occurred in the no-touch group. Conclusions SVGs harvested using our novel no-touch technique had similar pathological characteristics to those harvested using the original no-touch technique reported previously. Our no-touch technique maintained SVG patency and caused no severe wound complications. However, a large-scale, longitudinal study is required to accurately assess the clinical outcomes of our no-touch technique.
Background Cardiac calcified amorphous tumors (CATs) are non-neoplastic cardiac tumors of unknown origin and etiology. Several simultaneous CATs rarely occur in multiple cardiac chambers. Although CATs carry a benign prognosis, they have a risk of complications such as systemic embolism. Case presentation We report the case of a 79-year-old woman with two CATs and aortic regurgitation due to perforations of aortic cusps. She underwent surgical tumor resection with aortic valve replacement. The CATs were macroscopically and histologically different, which may suggest different developmental stages. One CAT was in the left atrium; it was less mobile and had nodular calcifications within dense fibrous tissue. The other CAT was in the left ventricular outflow tract; it was highly mobile, with nodular calcifications surrounded by amorphous fibrin and sanguineous deposits. The highly mobile CAT mechanically damaged the aortic cusps and caused perforations. The patient has survived over 2 years with no recurrence of the cardiac masses on echocardiography. Conclusion The patient underwent surgical resection for two CATs. The tumors occurred in different areas and had different macroscopic and histological characteristics. We recommend early resection for highly mobile CATs because of the high risks of embolization and injuries to the surrounding tissues.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.