Angiography Perfusion Research Articles

The Effect of Evaluating Perfusion with Infrared Fluorescent Angiography on Flap Survival in Head and Neck Free Flap Reconstruction.

Intraoperative fluid management is one of the most important factors affecting optimal perfusion in the microcirculatory area in patients that undergo flap surgery. While insufficient fluid administration in the intraoperative period leads to flap complications and organ dysfunction, volume load can cause complications such as edema in the denervated flap tissue, the opening of the sutures, or fat necrosis. The Infrared Fluorescent Angiography Perfusion Evaluation Device (SPY) is one of the many noninvasive techniques that evaluate the well-being of microcirculation at the tissue level. This device monitors and scores the perfusion distribution in the flap area. This retrospective study aimed to investigate the effect of fluid resuscitation in head and neck free flap transfer surgery on flap quality and patient outcomes according to the change in SPY scores. This study included 39 ASA I-II patients who were aged 18-60 years and underwent simultaneous free flap reconstruction of the head and neck between 2015 and 2021. Patients' blood pressure, body temperature, hemoglobin, pH, and lactate values were recorded at both baseline and end of the operation. Also, the SPY "Infrared Fluorescent Angiography Perfusion Evaluation Device" scores, the amount of intraoperative fluid and transfusion, bleeding and urine output, and the duration of mechanical ventilation, anesthesia and surgery, and the duration and amount of drainage, the length of stay in hospital and intensive care unit, and the presence of flap infection, detachment, necrosis and loss, and re-exploration rate were recorded for the patients. The difference between the first and last measured SPY values was observed to be positively correlated with the length of stay in the hospital and intensive care unit and the duration of drainage. There was a positive correlation between the length of stay in the hospital and intensive care unit and the duration of drainage, the amount of drainage, as well as the duration of anesthesia and the duration of surgery (p < 0.001). A positive correlation was found between the amount of drainage and the amount of crystalloid solution administered (r = 0.36, p < 0.05). In patients with flap infection, the difference between SPYfirst and SPYlast, the duration of anesthesia, and the duration of surgery were significantly higher. The amount of crystalloid solution given and bleeding and the duration of anesthesia and surgery were found to be significantly higher in mechanically ventilated patients (p < 0.05). It has been concluded that SPY-guided fluid management can be beneficial in preventing morbidities, such as extended hospital and intensive care stay, by reducing flap infection, mechanical ventilation duration, and drainage, with early diagnosis of insufficient perfusion.

Role of Angiographic Perfusion Score in Prediction of Perfusion Success and Risk Stratification in patient with STEMI Treated with Primary PCI

Role of Angiographic Perfusion Score in Prediction of Perfusion Success and Risk Stratification in patient with STEMI Treated with Primary PCI

Role of Angiographic Perfusion Score in Prediction of Perfusion Success and Risk Stratification Following Primary PCI versus Pharmaco-Invasive PCI for Anterior STEMI

Role of Angiographic Perfusion Score in Prediction of Perfusion Success and Risk Stratification Following Primary PCI versus Pharmaco-Invasive PCI for Anterior STEMI

Two-dimensional perfusion angiography permits direct visualization of redistribution of flow in hepatocellular carcinoma during b-TACE

ObjectivesTo demonstrate in vivo redistribution of the blood flow towards HCC’s lesions by utilizing two-dimensional perfusion angiography in b-TACE procedures.Material and methodsIn total, 30 patients with 35 HCC nodules treated in the period between January 2019 and November 2021. For each patient, a post-processing software leading to a two-dimensional perfusion angiography was applied on each angiography performed via balloon microcatheter, before and after inflation. On the colour map obtained, reflecting the evolution of contrast intensity change over time, five regions of interests (ROIs) were assessed: one on the tumour (ROI-t), two in the immediate peritumoural healthy liver parenchyma (ROI-ihl) and two in the peripheral healthy liver parenchyma (ROI-phl). The results have been interpreted with a novel in silico model that simulates the hemodynamics of the hepatic arterial system.ResultsAmong the ROIs drawn inside the same segment of target lesion, the time-to-peak of the ROI-t and of the ROI-ihl have a significantly higher mean value when the balloon was inflated compared with the ROIs obtained with deflated balloon (10.33 ± 3.66 s vs 8.87 ± 2.60 s (p = 0.015) for ROI-t; 10.50 ± 3.65 s vs 9.23 ± 2.70 s (p = 0.047) for ROI-ihl). The in silico model prediction time-to-peak delays when balloon was inflated, match with those observed in vivo. The numerical flow analysis shows how time-to-peak delays are caused by the obstruction of the balloon-occluded artery and the opening of intra-hepatic collateral.ConclusionThe measurements identify predictively the flow redistribution in the hepatic arteries during b-TACE, supporting a proper positioning of the balloon microcatheter.

Abstract TMP59: Automated Analysis of Dynamic Computed Tomographic Angiography Perfusion Maps Accurately Identifies Regional Hypoperfusion in Minor Stroke Patients

Background: Multi-phase computed tomographic angiography (mCTA) perfusion maps can help confirm the diagnosis of stroke which can be especially challenging when the symptoms are minor. The current study proposes an automated stroke detection method for identifying patient stroke status based on volumetric analysis of mCTA perfusion maps applied to minor stroke patient populations. Methods: Minor stroke patients were acutely imaged with mCTA and CTP. mCTA perfusion maps were created using an extreme gradient boosting trees classifier with a CTP TMAX&gt;6s ground truth. Volumes for each patient for each hemisphere were calculated from ten perfusion thresholds equally spaced from the minimum and maximum of the scaled perfusion map. The ten volumes form the variables in a logistic regression algorithm trained on the known stroke status of the hemisphere. 10-fold cross validation was implemented in addition to receiver-operating characteristic (ROC) analysis to produce accuracy, sensitivity, specificity, and area-under-curve (AUC). Results: In total 82 minor stroke patients (median age: 71, 48% female, median NIHSS: 3). 78% had identifiable intracranial occlusions. The analysis generated an ROC curve with an AUC of 81%. Cross-validation produced accuracy, specificity, and sensitivity of 76%, 87%, and 65%, respectively. Conclusion: The stroke detection model developed in the current study accurately categorized stroke and healthy hemispheres in minor stroke. Based on these results dynamic CTA perfusion could help diagnose stroke when the symptoms are mild thus providing accessible and accurate stroke diagnosis in primary stroke centres.

Post-Mortem Extracorporeal Membrane Oxygenation Perfusion Rat Model: A Feasibility Study.

The development of biomedical soft- or hardware frequently includes testing in animals. However, large efforts have been made to reduce the number of animal experiments, according to the 3Rs principle. Simultaneously, a significant number of surplus animals are euthanized without scientific necessity. The primary aim of this study was to establish a post-mortem rat perfusion model using extracorporeal membrane oxygenation (ECMO) in surplus rat cadavers and generate first post vivo results concerning the oxygenation performance of a recently developed ECMO membrane oxygenator. Four rats were euthanized and connected post-mortem to a venous-arterial ECMO circulation for up to eight hours. Angiographic perfusion proofs, blood gas analyses and blood oxygenation calculations were performed. The mean preparation time for the ECMO system was 791 ± 29 s and sufficient organ perfusion could be maintained for 463 ± 26 min, proofed via angiographic imaging and a mean femoral arterial pressure of 43 ± 17 mmHg. A stable partial oxygen pressure, a 73% rise in arterial oxygen concentration and an exponentially increasing oxygen extraction ratio up to 4.75 times were shown. Considering the 3Rs, the established post-mortal ECMO perfusion rat model using surplus animals represents a promising alternative to models using live animals. Given the preserved organ perfusion, its use could be conceivable for various biomedical device testing.

Immediate effect of anti-VEGF injections on optic nerve head: Correlation between intraocular pressure and anatomical peripapillary changes.

This study was designed to investigate retinal nerve fiber layer (RNFL) and radial peripapillary capillaries (RPC) changes on optical coherence tomography (OCT) angiography and OCT thickness alterations associated with acutely increased intraocular pressure after intravitreal injections. This observational clinical study was conducted on 35 eyes (35 patients) with treatment-naïve age-related macular degeneration (AMD) and type 1 or type 2 MNV were enrolled. All patients underwent anti-vascular endothelial grow factor (VEGF) intravitreal injections with 0.05-mL aflibercept (2 mg) between January 2022 and October 2022. Peripapillary OCT angiography perfusion density, retinal nerve fiber layer thickness, and intraocular pressure (IOP) were measured before and immediately after intravitreal injections. In particular, the analysis was performed at the following visits: (T0) 5 to 15 min before the injection of aflibercept; (T1) 2 to 5 min after the injection of aflibercept. Paired t-test was used to compare pre-injection and post-injection values. The mean baseline IOP (T0) value was 17.26 ± 2.4 mmHg and the immediate post-injection IOP (T1) mean value was 34.7 ± 11.50 mmHg (P < 0.01). The mean global RNFL thickness before and immediately after the injection was 100.9 ± 18.8 m and 98.6 ± 17.4 m (P = 0.001). Furthermore, the topographical RNFL analysis showed significant thickness reduction of the nasal and inferior sectors after the procedure when compared to T0 (P = 0.046 and P = 0.001). On the contrary, the mean RCP density changes at T1 did not reach statistically significant (P = 0.636). Furthermore, we found a significant negative correlation between the retinal nerve fiber layer global thickness and the IOP changes (Pearson's correlation = -0.126; P = 0.031). In particular, the nasal RNFL region showed a significant negative correlations with IOP values (Pearson's correlation = -0.198, P = 0,046). We reported acute IOP changes that are associated with reduced RNFL thickness in a group of patients undergoing intravitreal injections of anti-VEGF drugs for neovascular age-related macular degeneration. Moreover, topographical sub-analysis revealed that the nasal RNFL region is most prone to IOP fluctuations. This finding may explain the sudden visual acuity change in patients immediately after injection and may sustain injuries to optic nerve head structures producing glaucomatous damage.

Measurement of the Tumor-to-Normal Ratio for Radioembolization of Hepatocellular Carcinoma: A Prospective Study Comparing 2-Dimensional Perfusion Angiography, Technetium-99m Macroaggregated Albumin, and Yttrium-90 SPECT/CT

PurposeTo calculate the preradioembolic tumor-to-normal (T:N) ratio in hepatocellular carcinoma (HCC) using 2-dimensional (2D) perfusion angiography and compare it with that calculated using technetium-99m macroaggregated albumin (99mTc MAA) single-photon emission computed tomography (SPECT)/computed tomography (CT). Materials and MethodsThis prospective single-arm study enrolled 15 participants with HCC who underwent 2D perfusion angiography immediately before the enrollment and with the microcatheter located at the same location as 99mTc MAA injection, after which SPECT/CT was performed. Quantitative digital subtraction angiography was used to calculate the area under the curve for the tumor and normal hepatic parenchyma and subsequently calculate the T:N ratio. The T:N ratio was calculated from the 99mTc MAA SPECT/CT and post–yttrium-90 bremsstrahlung SPECT/CT using dosimetry software. ResultsThe mean participant age was 64.1 years ± 9.8, and the study included 14 (93%) men and 1 (7%) woman. The mean tumor size was 4.1 cm (SD ± 2.4), and all participants received segmental treatments with glass microspheres. The mean T:N ratio calculated by 99mTc MAA SPECT/CT was 2.28 (SD ± 0.89) vs 2.25 (SD ± 0.99) calculated by 2D perfusion angiography (P = .45). For the 13 participants who underwent selective internal radiation therapy (transarterial radioembolization), there was no significant difference between the T:N ratios calculated by 2D perfusion angiography and post-90Y SPECT/CT (2.25 [SD ± 1.05] vs 1.91 [SD ± 0.39]; P = .12). ConclusionsThe T:N ratio calculated by 2D perfusion angiography correlated well with that calculated by 99mTc MAA SPECT/CT.

DSA-Based 2D Perfusion Measurements in Delayed Cerebral Ischemia to Estimate the Clinical Outcome in Patients with Aneurysmal Subarachnoid Hemorrhage: A Technical Feasibility Study.

(1) Background: To predict clinical outcomes in patients with aneurysmal subarachnoid hemorrhage (aSAH) and delayed cerebral ischemia (DCI) by assessment of the cerebral perfusion using a 2D perfusion angiography (2DPA) time-contrast agent (CA) concentration model. (2) Methods: Digital subtraction angiography (DSA) data sets of n = 26 subjects were acquired and post-processed focusing on changes in contrast density using a time-concentration model at three time points: (i) initial presentation with SAH (T0); (ii) vasospasm-associated acute clinical impairment (T1); and (iii) directly after endovascular treatment (T2) of SAH-associated large vessel vasospasm (LVV), which resulted in n = 78 data sets. Maximum slope (MS in SI/ms), time-to-peak (TTP in ms), and maximum amplitude of a CA bolus (dSI) were measured in brain parenchyma using regions of interest (ROIs). First, acquired parameters were standardized to the arterial input function (AIF) and then statistically analyzed as mean values. Additionally, data were clustered into two subsets consisting of patients with regredient or with stable/progredient symptoms (or Doppler signals) after endovascular treatment (n = 10 vs. n = 16). (3) Results: Perfusion parameters (MS, TTP, and dSI) differed significantly between T0 and T1 (p = 0.003 each). Significant changes between T1 and T2 were only detectable for MS (0.041 ± 0.016 vs. 0.059 ± 0.026; p = 0.011) in patients with regredient symptoms at T2 (0.04 ± 0.012 vs. 0.066 ± 0.031; p = 0.004). For dSI, there were significant differences between T0 and T2 (5095.8 ± 2541.9 vs. 3012.3 ± 968.3; p = 0.001), especially for those with stable symptoms at T2 (5685.4 ± 2967.2 vs. 3102.8 ± 1033.2; p = 0.02). Multiple linear regression analysis revealed that a) the difference in MS between T1 and T2 and b) patient's age (R = 0.6; R2 = 0.34; p = 0.009) strongly predict the modified Rankin Scale (mRS) at discharge. (4) Conclusions: 2DPA allows the direct measurement of treatment effects in SAH associated DCI and may be used to predict outcomes in these critically ill patients.

Towards quantitative digital subtraction perfusion angiography: An animal study.

X-ray digital subtraction angiography (DSA) is the imaging modality for peri-procedural guidance and treatment evaluation in (neuro-) vascular interventions. Perfusion image construction from DSA, as a means of quantitatively depicting cerebral hemodynamics, has been shown feasible. However, the quantitative property of perfusion DSA has not been well studied. To comparatively study the independence of deconvolution-based perfusion DSA with respect to varying injection protocols, as well as its sensitivity to alterations in brainconditions. We developed a deconvolution-based algorithm to compute perfusion parametric images from DSA, including cerebral blood volume (CBV ), cerebral blood flow (CBF ), time to maximum (Tmax), and mean transit time (MTT ) and applied it to DSA sequences obtained from two swine models. We also extracted the time intensity curve (TIC)-derived parameters, that is, area under the curve (AUC), peak concentration of the curve, and the time to peak (TTP) from these sequences. Deconvolution-based parameters were quantitatively compared to TIC-derived parameters in terms of consistency upon variations in injection profile and time resolution of DSA, as well as sensitivity to alterations of cerebralcondition. Comparing to TIC-derived parameters, the standard deviation (SD) of deconvolution-based parameters (normalized with respect to the mean) are two to five times smaller, indicating that they are more consistent across different injection protocols and time resolutions. Upon ischemic stroke induced in a swine model, the sensitivities of deconvolution-based parameters are equal to, if not higher than, those of TIC-derivedparameters. In comparison to TIC-derived parameters, deconvolution-based perfusion imaging in DSA shows significantly higher quantitative reliability against variations in injection protocols across different time resolutions, and is sensitive to alterations in cerebral hemodynamics. The quantitative nature of perfusion angiography may allow for objective treatment assessment in neurovascularinterventions.

Evaluating clinical near-infrared surgical camera systems with a view to optimizing operator and computational signal analysis.

As clinical evidence on the colorectal application of indocyanine green (ICG) perfusion angiography accrues, there is also interest in computerizing decision support. However, user interpretation and software development may be impacted by system factors affecting the displayed near-infrared (NIR) signal. We aim to assess the impact of camera positioning on the displayed NIR signal across different open and laparoscopic camera systems. The effects of distance, movement, and target location (center versus periphery) on the displayed fluorescence signal of different systems were measured under electromagnetic stereotactic guidance from an ICG-albumin model and in vivo during surgery. Systems displayed distinct fluorescence performances with variance apparent with scope optical lens configuration (0deg versus 30deg), movement, target positioning, and distance. Laparoscopic system readings fitted inverse square function distance-intensity curves with one device and demonstrated a direction dependent sigmoid curve. Laparoscopic cameras presented central targets as brighter than peripheral ones, and laparoscopes with angled optical lens configurations had a diminished field of view. One handheld open system also showed a distance-intensity relationship, whereas the other maintained a consistent signal despite distance, but both presented peripheral targets brighter than central ones. Optimal clinical use and signal computational development requires detailed appreciation of system behaviors.

Clinical Applications of Quantitative Perfusion Imaging with a C-Arm Flat-Panel Detector-A Systematic Review.

C-arm systems with digital flat-panel detectors are used in interventional radiology and hybrid operating rooms for visualizing and performing interventions on three-dimensional structures. Advances in C-arm technology have enabled intraoperative quantitative perfusion imaging with these scanners. This systematic review provides an overview of flat-panel detector C-arm techniques for quantifying perfusion, their clinical applications, and their validation. A systematic search was performed for articles published between January 2000 and October 2022 in which a flat-panel detector C-arm technique for quantifying perfusion was compared with a reference technique. Nine articles were retrieved describing two techniques: two-dimensional perfusion angiography (n = 5) and dual-phase cone beam computed tomography perfusion (n = 4). A quality assessment revealed no concerns about the applicability of the studies. The risk of bias was relatively high for the index and reference tests. Both techniques demonstrated potential for clinical application; however, weak-to-moderate correlations were reported between them and the reference techniques. In conclusion, both techniques could add new possibilities to treatment planning and follow-up; however, the available literature is relatively scarce and heterogeneous. Larger-scale randomized prospective studies focusing on clinical outcomes and standardization are required for the full understanding and clinical implementation of these techniques.

Changes in perfusion angiography after IVC filter placement and retrieval

Inferior vena cava (IVC) filters are posited to effect flow dynamics, causing turbulence, vascular remodeling and eventual thrombosis; however, minimal data exists evaluating hemodynamic effects of IVC filters in vivo. The purpose of this study was to determine differences in hemodynamic flow parameters acquired with two-dimension (2D)-perfusion angiography before and after IVC filter placement or retrieval. 2D-perfusion images were reconstructed retrospectively from digital subtraction angiography from a cohort of 37 patients (13F/24M) before and after filter placement (n = 18) or retrieval (n = 23). Average dwell time was 239.5 ± 132.1 days. Changes in the density per pixel per second within a region of interest (ROI) were used to calculate contrast arrival time (AT), time-to-peak (TTP), wash-in-rate (WIR), and mean transit time (MTT). Measurements were obtained superior to, inferior to, and within the filter. Differences in hemodynamic parameters before and after intervention were compared, as well as correlation between parameters versus filter dwell time. A P value with Bonferroni correction of <.004 was considered statistically significant. After placement, there was no difference in any 2D-perfusion variable. After retrieval, ROIs within and inferior to the filter showed a significantly shorter TTP (1.7 vs 1.4 s, P = .004; 1.5 vs 1.3 s, P = .001, respectively) and MTT (1.7 vs 1.4 s, P = .003; 1.5 vs 1.2 s, P = .002, respectively). Difference in variables showed no significant correlation when compared to dwell time. 2D-perfusion angiography is feasible to evaluate hemodynamic effects of IVC filters in vivo. TTP and MTT within and below the filter after retrieval were significantly changed, without apparent correlation to dwell time, suggesting a functional hemodynamic delay secondary to filter presence.

2D perfusion angiography: an alternative method to evaluate endovascular intervention for acute lower limb ischemia

BackgroundDespite advances in endovascular techniques to treat acute limb ischemia (ALI), evaluation of clinical outcomes for revascularization remains challenging, especially the accurate quantification of post-endovascular limb perfusion. This study aimed to investigate the accuracy and value of 2D perfusion angiography to evaluate endovascular intervention for ALI.MethodsA total of 47 patients with ALI were retrospectively analyzed. The transcutaneous oxygen partial pressure (TcPO2) was obtained using laser Doppler blood perfusion monitoring. The ankle-brachial index (ABI) and angiographic images were obtained before and after endovascular intervention. iFlow imaging was used to obtain color-coded images. Regions of interest (ROIs) at the femoral head, knee joint, and ankle joint were selected to obtain the time to peak (TTP). The differences in the TTP between the knee and femoral head regions (TTP difference in the knee area) and between the ankle and knee regions (TTP difference in the ankle area) were observed. The TTP, ABI, and TcPO2 between the complete response (CR), partial response (PR), no response (NR), and amputation (AM) groups were compared. The correlation between TTP changes in the ankle area (ΔTTP) and changes in ABI (ΔABI)/changes in TcPO2 (ΔTcPO2) was analyzed.ResultsThere was a significant increase in both TcPO2 and ABI compared with the pre-intervention values (27.75 ± 5.32 vs 40.92 ± 4.62, and 0.35 ± 0.16 vs 0.79 ± 0.15, respectively, all p < 0.01). The post-intervention TTP differences in the knee areas (5.12 ± 2.45 s) and ankle areas (6.93 ± 4.37 s) were significantly faster than pre-intervention TTP differences (7.03 ± 2.57 s and 10.66 ± 4.07 s, respectively, all p < 0.05). The post-operative TTP in the ankle area, post-operative TTP difference in the ankle area, and ΔTTP in the AM group were higher than the values in the CR and PR groups. The ΔTTP demonstrated strong correlation with ΔABI (r = −0.722, p < 0.01) and ΔTcPO2 (r = −0.734, p < 0.01).Conclusions2D perfusion angiography with enhanced visual and quantitative analysis exhibits great potential to evaluate the efficacy of endovascular intervention, and provides a quantitative and sensitive tool to evaluate post-endovascular limb perfusion for ALI patients.

Feasibility of deconvolution-based multiphase CT angiography perfusion maps in acute ischemic stroke: Simulation and concordance with CT perfusion

ObjectivesIntegration of CT perfusion (CTP) with requisite non-contrast CT and CT angiography (CTA) stroke imaging may allow efficient stroke lesion volume measurement. Using surrogate images from CTP, we simulated the feasibility of using multiphase CTA (mCTA) to generate perfusion maps and assess target mismatch profiles. Materials and methodsPatients with acute ischemic stroke who received admission CTP were included in this study. Four CTP images (surrogate mCTA, one pre-contrast and three post-contrast, starting at the arterial peak then at 8 s intervals) were selected according to the CTP arterial time-density curve to simulate non-contrast CT and mCTA images. Cerebral blood flow (CBF) and Tmax maps were calculated using the same model-based deconvolution algorithm for the standard CTP and surrogate mCTA studies. Infarct and penumbra were delineated with CBF < 20% and Tmax > 6 s threshold, respectively. Classification accuracy of surrogate mCTA target mismatch (infarct <70 ml; penumbra ≥15 ml; mismatch ratio ≥1.8) with respect to standard CTP was assessed. Agreement between infarct and penumbra volumes from standard CTP and surrogate mCTA maps were evaluated by Bland-Altman analysis. ResultsOf 34 included patients, 28 had target mismatch and 6 did not by standard CTP. Accuracy of classifying target mismatch profiles with surrogate mCTA was 79% with respect to that from standard CTP. Mean ± standard deviation of differences (standard CTP minus surrogate mCTA) of infarct and penumbra volumes were 9.8 ± 14.8 ml and 20.1 ± 45.4 ml, respectively. ConclusionsSurrogate mCTA ischemic lesion volumes agreed with those from standard CTP and may be an efficient alternative when CTP is not practical.

Core-Shell Structured Porous Calcium Phosphate Bioceramic Spheres for Enhanced Bone Regeneration.

Adequate new bone regeneration in bone defects has always been a challenge as it requires excellent and efficient osteogenesis. Calcium phosphate (CaP) bioceramics, including hydroxyapatite (HA) and biphasic calcium phosphates (BCPs), have been extensively used in clinical bone defect filling due to their good osteoinductivity and biodegradability. Here, for the first time, we designed and fabricated two porous CaP bioceramic granules with core-shell structures, named in accordance with their composition as BCP@HA and HA@BCP (core@shell). The spherical shape and the porous structure of these granules were achieved by the calcium alginate gel molding technology combined with a H2O2 foaming process. These granules could be stacked to build a porous structure with a porosity of 65-70% and a micropore size distribution between 150 and 450 μm, which is reported to be good for new bone ingrowth. In vitro experiments confirmed that HA@BCP bioceramic granules could promote the proliferation and osteogenic ability when cocultured with bone marrow mesenchymal stem cells, while inhibiting the differentiation of RAW264.7 cells into osteoclasts. In vivo, 12 weeks of implantation in a critical-sized femoral bone defect animal model showed a higher bone volume fraction and bone mineral density in the HA@BCP group than in the BCP@HA or pure HA or BCP groups. From histological analysis, we discovered that the new bone tissue in the HA@BCP group was invading from the surface to the inside of the granules, and most of the bioceramic phase was replaced by the new bone. A higher degree of vascularization at the defect region repaired by HA@BCP was revealed by 3D microvascular perfusion angiography in terms of a higher vessel volume fraction. The current study demonstrated that the core-shell structured HA@BCP bioceramic granules could be a promising candidate for bone defect repair.

Review on Anastomotic Leak Rate after ICG Angiography during Minimally Invasive Colorectal Surgery

Summary Colorectal cancer is the 3rd most common type of cancer worldwide. The most devastating complication after colorectal surgery remains the anastomotic leak (AL). Many techniques have been developed to reduce its rate. One such new method is perfusion angiography using indocyanine green (ICG). A literary search in PUBMED on 1.03.2021 for full-text English articles published between 2014 and 2021 was performed. ICG, colorectal cancer, and angiography were the keywords we used. The review was performed following the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The literature search yielded 27 results when searching the database of PUBMED with the above keywords. Twenty-one out of 27 identified articles were included. Six were excluded from the analysis – four case reports, one review on the evolution of treating gastrointestinal cancers, and one containing no information on AL rate with ICG. One included article was RCT, sixteen were cohort studies, and four were meta-analyses or reviews. All articles reported a reduction in the anastomotic leak rate. However, the reduction was significant only in nine of them. Anastomotic leak is a severe complication and a subject of extensive research. Perfusion angiography with ICG is a step towards predicting and preventing AL, although it does not guarantee success in all cases.

2D perfusion angiography as quantitative method to evaluate iloprost effect on foot circulation.

Background: Two-dimensional (2D) perfusion angiography is useful for the evaluation of foot perfusion in patients with critical limb-threatening ischemia (CLTI). Iloprost is a synthetic prostacyclin analogue presenting vasodilating properties. Aim of this study was to demonstrate the utility of 2D perfusion angiography as quantitative method to evaluate iloprost effect on foot circulation. Patients and methods: Between January 2020 and June 2020 25 patients with CLTI underwent below-the-knee (BTK) endovascular revascularization, intra-arterial administration of iloprost, and assessment of foot perfusion by 2D perfusion angiography. Iloprost was administered as an intra-arterial bolus of 3 μg over 1-3 minutes immediately after BTK revascularization. The 2D perfusion angiography was performed in a standardized manner with a 5-F catheter placed into the popliteal artery. A wide region of interest (ROI) was identified to assess the foot perfusion. Time-density curves were calculated by the perfusion software. Changes of the overall time-density curves before and after the administration of iloprost were evaluated. Results: Endovascular revascularization was successful in all cases. The mean reduction of systolic pressure value after iloprost administration was 23.1 mmHg. Eight patients (32%) experienced a minor complication (6 cutaneous rush, 2 symptomatic hypotension >40mmHg). In 20 patients the time-density curves under ROI increased after the intra-arterial administration of iloprost (+31.6%, range from +4.9% to +78.7%). Five patients had no modification or a slight decrease of foot perfusion after iloprost administration (non-responders patients). Conclusions: Patients undergoing intra-arterial administration of iloprost accounted for a not negligible rate of minor complications. 2D perfusion angiography was valuable as quantitative method to evaluate the iloprost effect on foot circulation. This technique could be useful to classify the patients in responders or non-responders to iloprost therapy.

Distal Intracoronary Delivery of Epinephrine versus Verapamil to Prevent No-Reflow During Primary Percutaneous Coronary Intervention: A Randomized, Open-Label, Trial

Background: Previous trials showed a promising potential use of epinephrine in the treatment of no-reflow phenomenon (the no-reflow phenomenon is multiple pathogenetic processes, which may be attributed to ischemic injuries, distal atherothrombotic embolization, coronary-microcirculation susceptibility to injury, and reperfusion injuries (6)). This study aimed to compare the safety and efficacy of distal intracoronary delivery of epinephrine versus verapamil to prevent no-reflow during primary percutaneous coronary intervention (PPCI). Materials and Methods: We conducted a randomized, open-label, trial on patients undergoing PPCI. Patients were randomized to one of three groups: group I who received distal intracoronary administration of epinephrine; group II who received verapamil; and group III who served as a control group. The primary endpoint in our study was the incidence of no-reflow, defined as a post-procedural (Thrombolysis in Myocardial Infarction) TIMI flow grade (TFG) is &lt; 3 or, in the case of a TFG of 3, when TIMI myocardial perfusion grade (TMPG) is 0 or 1. Results: A total of 120 patients were randomized. The angiographic flow and perfusion parameters were significantly improved in group I and II versus the control group, with better results in epinephrine group only TMPG3 was significantly higher with epinephrine (77.5%) than verapamil (55%) (p = 0.037) and TMPG2 was higher in verapamil (32.5%) than epinephrine (7.5%) (p = 0.003). No reflow is lower with epinephrine than verapamil (25% vs 27.5%); however, with no statistically significant difference (P=0.785). Patients in the three groups has no statistical significant difference in (MACE) or heart failure hospitalization. Conclusion: Epinephrine and verapamil are safe and effective in managing patients with no-reflow during PPCIs. Further studies with a larger sample and a longer duration of follow-up are required to confirm these findings

USPIO-SWI Shows Fingolimod Enhanced Alteplase Action on Angiographic Reperfusion in eMCAO Rats.

Noninvasive evaluation of the status of cerebral arteriole perfusion remains a practical challenge in murine stroke models, because conventional magnetic resonance imaging (MRI) is no longer capable of capturing these very small vessels. To investigate the feasibility of ultrasmall superparamagnetic iron oxide particles (USPIO)-based susceptibility weighted imaging (SWI)-MRI (USPIO-SWI) and T2* map-MRI (USPIO-T2* map) for monitoring angiographic perfusion in stroke rats. A preclinical randomized controlled trial. Normal rats (N= 9), embolic middle cerebral artery occlusion (eMCAO) rats (N= 66). 7 T; T2* map (multigradient echo), SWI (3D gradient echo). Experiment 1: To develop a method for angiographic reperfusion evaluation with USPIO-SWI. Normal rats were used to optimize the USPIO dosage (5.6, 16.8, and 56 mg/kg ferumoxytol) as well as scan time points for cerebral arterioles. Contrast-to-noise ratio (CNR) was measured. Stroke rats were further used and the number of visual cortical vessels were counted. Experiment 2: To examine whether fingolimod (lymphocytes inhibitor) enhances the action of tissue plasminogen activator (tPA) in eMCAO rats on cerebral angiographic reperfusion. Mann-Whitney test and two way-ANOVA were used. P< 0.05 was considered statistically significant. CNR values of cerebral cortical penetrating arteries in normal rats were significantly increased to 4.4 ± 0.5 (5.6 mg/kg), 6.1 ± 0.5 (16.8 mg/kg), and 3.4 ± 0.9 (56 mg/kg) after USPIO injection. The number of visual cortical vessels on USPIO-SWI images in ischemic regions was significantly less than in control regions (5 ± 2 vs. 56 ± 20) of eMCAO rats. Compared with eMCAO rats who received tPA only, eMCAO rats who received the combination of fingolimod and tPA exhibited significantly higher proportion of complete angiographic reperfusion (69% vs. 17%). This study supports the feasibility of angiographic perfusion evaluation with USPIO-SWI in stroke rats. 2 TECHNICAL EFFICACY STAGE: 1.