Dataset Information

Intraoperative evaluation of revascularization effect on ischemic muscle hemodynamics using near-infrared diffuse optical spectroscopies.

ABSTRACT: Arterial revascularization in patients with peripheral arterial disease (PAD) reestablishes large arterial blood supply to the ischemic muscles in lower extremities via bypass grafts or percutaneous transluminal angioplasty (PTA). Currently no gold standard is available for assessment of revascularization effects in lower extremity muscles. This study tests a novel near-infrared diffuse correlation spectroscopy flow-oximeter for monitoring of blood flow and oxygenation changes in medial gastrocnemius (calf) muscles during arterial revascularization. Twelve limbs with PAD undergoing revascularization were measured using a sterilized fiber-optic probe taped on top of the calf muscle. The optical measurement demonstrated sensitivity to dynamic physiological events, such as arterial clamping/releasing during bypass graft and balloon inflation/deflation during PTA. Significant elevations in calf muscle blood flow were observed after revascularization in patients with bypass graft (+48.1 ± 17.5%) and patients with PTA (+43.2 ± 11.0%), whereas acute post-revascularization effects in muscle oxygenation were not evident. The decoupling of flow and oxygenation after revascularization emphasizes the need for simultaneous measurement of both parameters. The acute elevations/improvements in calf muscle blood flow were associated with significant improvements in symptoms and functions. In total, the investigation corroborates potential of the optical methods for objectively assessing the success of arterial revascularization.

SUBMITTER: Yu G

PROVIDER: S-EPMC3061333 | biostudies-other | 2011 Feb

REPOSITORIES: biostudies-other

ACCESS DATA

Similar Datasets

Project description:BACKGROUND:Although real-time localization of gliomas has improved with intraoperative image guidance systems, these tools are limited by brain shift, surgical cavity deformation, and expense. OBJECTIVE:To propose a novel method to perform near-infrared (NIR) imaging during glioma resections based on preclinical and clinical investigations, in order to localize tumors and to potentially identify residual disease. METHODS:Fifteen patients were identified and administered a Food and Drug Administration-approved, NIR contrast agent (Second Window indocyanine green [ICG], 5 mg/kg) before surgical resection. An NIR camera was utilized to localize the tumor before resection and to visualize surgical margins following resection. Neuropathology and magnetic resonance imaging data were used to assess the accuracy and precision of NIR fluorescence in identifying tumor tissue. RESULTS:NIR visualization of 15 gliomas (10 glioblastoma multiforme, 1 anaplastic astrocytoma, 2 low-grade astrocytoma, 1 juvenile pilocytic astrocytoma, and 1 ganglioglioma) was performed 22.7 hours (mean) after intravenous injection of ICG. During surgery, 12 of 15 tumors were visualized with the NIR camera. The mean signal-to-background ratio was 9.5 ± 0.8 and fluorescence was noted through the dura to a maximum parenchymal depth of 13 mm. The best predictor of positive fluorescence was enhancement on T1-weighted imaging; this correlated with signal-to-background ratio (P = .03). Nonenhancing tumors did not demonstrate NIR fluorescence. Using pathology as the gold standard, the technique demonstrated a sensitivity of 98% and specificity of 45% to identify tumor in gadolinium-enhancing specimens (n = 71). CONCLUSION:With the use of Second Window ICG, gadolinium-enhancing tumors can be localized through brain parenchyma intraoperatively. Its utility for margin detection is promising but limited by lower specificity. ABBREVIATIONS:5-ALA, 5-aminolevulinic acidEPR, enhanced permeability and retentionFDA, Food and Drug AdministrationGBM, glioblastomaICG, indocyanine greenNIR, near-infraredNPV, negative predictive valuePPV, positive predictive valueROC, receiver operating characteristicROI, region of interestSBR, signal-to-background ratioWHO, World Health Organization.

Project description:ImportanceIdentification of the tumor margin during surgery is important for precise minimal resection of lung tumors. Intravenous injection of indocyanine green (ICG) has several limitations when used for intraoperative visualization of lung cancer.ObjectivesTo describe a technique for intraoperative visualization of lung tumor margin using ICG inhalation and evaluate the clinical applicability of the technique in mouse and rabbit lung tumor models as well as lung specimens of patients with lung tumors.Design, setting, and participantsIn lung tumor models of both mice and rabbits, the distribution of inhaled ICG in the lung tumor margin was investigated in vivo and ex vivo using a near-infrared imaging system. Lung tumor margin detection via inhalation of ICG was evaluated by comparing the results obtained with those of the intravenous injection method (n = 32, each time point for 4 mice). Based on preclinical data, use of ICG inhalation to help detect the tumor margin in patients with lung cancer was also evaluated (n = 6). This diagnostic study was conducted from May 31, 2017, to March 30, 2019.Main outcomes and measuresThe use of tumor margin detection by inhaled ICG was evaluated by comparing the inhaled formulation with intravenous administration of ICG.ResultsFrom 10 minutes after inhalation of ICG to 24 hours, the distribution of ICG in the lungs was significantly higher than that in other organs (signal to noise ratio in the lungs: 39 486.4; interquartile range [IQR], 36 983.74-43 592.5). Ex vivo and histologic analysis showed that, in both lung tumor models, inhaled ICG was observed throughout the healthy lung tissue but was rarely found in tumor tissue. The difference in the fluorescent signal between healthy and tumor lung tissues was associated with the mechanical airway obstruction caused by the tumor and with alveolar macrophage uptake of the inhaled ICG in healthy tissues. Inhalation at a 20-fold lower dose of ICG had a 2-fold higher efficiency for tumor margin detection than did the intravenous injection (2.9; IQR, 2.7-3.2; P < .001).Conclusions and relevanceThe results of this study suggest that lung-specific inhalation delivery of ICG is feasible and may be useful for the intraoperative visualization of lung tumor margin in clinical practice.

Dataset Information

Intraoperative evaluation of revascularization effect on ischemic muscle hemodynamics using near-infrared diffuse optical spectroscopies.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets