ARTICLE | doi:10.20944/preprints202109.0229.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: intraoperative photodiagnosis; malignant glioma; fluorescence-guided surgery; intraoperative cytology; fluorescence microscope
Online: 14 September 2021 (10:02:54 CEST)
Objective: Surgical eradication of malignant glioma cells is theoretically impossible. Therefore, reducing the number of remaining tumor cells around the brain-tumor interface (BTI) is crucial for achieving satisfactory clinical results. The usefulness of fluorescence-guided resection for the treatment of malignant glioma was recently reported, but the detection of infiltrating tumor cells in the BTI using a surgical microscope is not realistic. Therefore, we developed an intraoperative rapid fluorescence cytology system, and evaluated its clinical feasibility for the management of malignant glioma. Materials and methods: Twenty-five selected patients with malignant glioma (newly diagnosed: 17; recurrent: 8) underwent surgical resection under photodiagnosis using photosensitizer Talaporfin sodium and a semiconductor laser. Intraoperatively, a crush smear preparation was made from a tiny amount of tumor tissue, and the fluorescence emitted upon 620/660 nm excitation was evaluated rapidly using a compact fluorescence microscope in the operating theater. Results: Fluorescence intensities of tumor tissues measured using a surgical microscope correlated with the tumor cell densities of tissues evaluated by measuring the red fluorescence emitted from the cytoplasm of tumor cells using a fluorescence microscope. A “weak fluorescence” indicated a reduction in the tumor cell density, whereas “no fluorescence” did not indicate the complete eradication of the tumor cells, but indicated that few tumor cells were emitting fluorescence.Conclusion: The rapid intraoperative detection of fluorescence from glioma cells using a compact fluorescence microscope was a useful to evaluate the presence of tumor cells in the resection cavity walls, and provides surgical implications for the more complete resection of malignant gliomas.
REVIEW | doi:10.20944/preprints202205.0383.v1
Subject: Medicine & Pharmacology, Other Keywords: colorectal; fluorescence; ICG; ICG-NIR; colorectal surgery; intraoperative staining; q-ICG
Online: 27 May 2022 (11:59:25 CEST)
This review looks at the use of indocyanine green (ICG) in colorectal surgery, from a quantitative point of view. The main benefits of the ICG technique in colorectal surgery, can be summarized as follows: a)in the realization of the intraoperative fluorescence angiography as an adjuvant in the process of anastomosis, b)in the fluorescence-guided detection of lymph node metastases in colorectal cancer and, also, the sentinel lymph node technique, which was proven better than formal methods in some studies, c) marking with positive fluorescence a liver nodule as small as "just" 200 tumor cells, d) offering assistance in the diagnosis of a fistula, e)in the possibility to be used for tumor tattooing also, f)providing help in maintaining a clean surgical field and preventing wound infection in abdominoperineal resection. Apart from the qualitative intraoperative use of ICG, the method can be employed in association with quantitative methods, such as maximum intensity, relative maximum intensity, and various parameters of the inflow (time-to-peak, slope, and t1/2max), this latter category being more significantly associated with anastomotic leakage.
ARTICLE | doi:10.20944/preprints202102.0384.v1
Subject: Medicine & Pharmacology, Allergology Keywords: acute mesenteric ischemia (AMI); optical coherence tomography (OCT); optical coherence angiography (OCA); intraoperative diagnostics; gut vitality; image assessment
Online: 17 February 2021 (12:02:23 CET)
Introduction: Despite the introduction of increasingly multifaceted diagnostic techniques and the general progress of emergency abdominal and vascular surgery, the outcome of treatment of patients with acute impaired intestinal circulation remains unsatisfactory. The non-invasive and high-resolution technique of optical coherence tomography (OCT) can be used intraoperatively to assess intestine viability and associated conditions that frequently emerge under conditions of impaired blood circulation. This study aims to demonstrate the effectiveness of multimodal (MM) OCT for intraoperative diagnostics of both the microstructure (cross-polarization OCT mode) and microcirculation (OCT angiography mode) of the small intestine wall in patients with acute mesenteric ischemia (AMI). Methods and Participants: A total of 18 patients were enrolled in the study. Nine of them suffered from AMI in segments II-III of the superior mesenteric artery (AMI group), where the ischemic segments of the intestine were examined. Nine others were operated for adenocarcinoma of the colon (control group), thus allowing areas of their normal small intestine to be examined for comparison. Data on the microstructure and microcirculation in the walls of the small intestine were obtained intraoperatively from the side of the serous membrane using the MM OCT system (IAP RAS, Russia) before bowel resection. The MM OCT data were compared with the results of histological examination. Results: The study finds that MM OCT visualized the damage to serosa, muscularis externa, and blood vessels localized in these layers in 100% of AMI cases. It also visualized the submucosa in 33.3% of AMI cases. The MM OCT image of non-ischemic (control group), viable ischemic and necrotic small intestines (AMI group) differed significantly across stratification of the distinguishable layers, the severity of intermuscular fluid accumulations and the type and density of the vasculature. Conclusion: The MM OCT diagnostic procedure optimally meets the requirements of emergency surgery. Data on the microstructure and microcirculation of the intestinal wall can be obtained simultaneously in real time without requiring contrast agent injections. The depth of visualization of the intestinal wall from the side of the serous membrane is sufficient to assess the volume of the affected tissues. However, the methodology for obtaining MM OCT data needs to be improved to minimize the motion artefacts generated in actual clinical conditions.