Assessment Of Tissue Perfusion Research Articles

Use of Ambient Light Compatible Fluorescence-Guided Surgical Technology for Objective Assessment of Flap Perfusion in Autologous Breast Reconstruction.

Decreased autologous flap vascular perfusion can lead to secondary procedures. Fluorescence angiography during surgery reduces the probability of repeat surgery but suffers from interpretation variability. Recently, the OnLume Avata System was developed, which evaluates real-time vascular perfusion in ambient light. This study aims to predict complications in autologous breast reconstruction using measures of relative intensity (RI) and relative area (RA). Patients undergoing autologous breast reconstruction underwent intraoperative tissue perfusion assessment using the OnLume Avata System. Post-hoc image annotation was completed by labeling areas of the flap interpreted to be "Well Perfused," "Questionably Perfused," and "Under Perfused." RIs and RAs were calculated for the marked areas. Primary complications of interest were overall complication rate, fat and mastectomy skin flap necrosis, and surgical revision. Logistic regression was applied to determine the odds of developing a complication based on RI and RA for each image. A total of 25 patients (45 flaps) were included. In total, 17 patients (68%) developed at least one complication. Patients who developed any complication (p = 0.02) or underwent a surgical revision for complications (p = 0.02) had statistically lower RI of under-perfused portions of the flap. Patients with greater areas of under-perfused flap had a significantly higher risk of developing fat necrosis (odds ratio [OR]: 5.71, p = 0.03) and required a revision operation (OR: 1.10, p = 0.01). Image-based interpretation using the OnLume Avata System correlated with the risk of developing postoperative complications that standard fluorescence imaging systems may not appreciate. This information can benefit surgeons to improve perfusion assessment and intraoperative decision-making.

History of contrast enhanced ultrasound (CEUS).

The 50th year of the European Federation of Societies in Ultrasound in Medicine and Biology (EFSUMB) has been celebrated 2022 publishing articles on the history of US. Contrast enhanced ultrasound (CEUS) allows to visualize blood flow and tissue perfusion. CEUS has proven to be safe without risk of nephrotoxicity. The availability of a contrast agent (tracer) for ultrasound imaging allows for the first time a dynamic assessment of tissue perfusion (blood flow and wash-in/wash-out pattern) which is an essential part for the detection and characterisation of pathological tissue and abnormal organ function. It was an outstanding achievement of academic centers in close cooperation with EFSUMB to investigate and validate the clinical potential of this new technology for the diagnosis and monitoring of various diseases and to develop clinical guidelines based on an in-depth assessment of the existing scientific publications. An important part of the implementation of CEUS in clinical practice was the development of contrast-specific imaging modes on the ultrasound scanners (in close cooperation with the machine manufacturers), the optimization of the machine setups for contrast imaging and the education provided to clinical users in form of workshops, webinars, textbooks and scientific congresses.

The intraoperative application of indocyanine green (ICG), in breast reconstructive surgery using a latissimus dorsi flap, as a preventive factor for tissue ischemia and postoperative complications

Introduction: Breast cancer is the most frequent cancer among women. Nowadays more and more women decide to undergo breast reconstruction, both using implants as well as autologous flaps. The most important factor in avoiding bad wound healing is the preservation of blood supply and good tissue perfusion. Latissimus dorsi flap is a commonly used method, mainly reserved for irradiated patients, delayed reconstruction, or salvage procedures. With damaged tissues, objectively assessing the conditions is much more difficult than in primary surgery.Aim: The aim of the study is to present the intraoperative application of ICG, in breast reconstructive surgery with a latissimus dorsi flap, as a preventive factor for tissue ischemia and postoperative complications. Materials and methods: A single-center retrospective review of the outcomes of 12 patients who underwent breast reconstruction using an LD flap, with an intraoperative assessment of flap blood supply using ICG. Patient characteristics, comorbidities, and smoking were taken into account. Results: In two cases, after an initial assessment of tissue perfusion, it was decided to resection the distal part of the flap with less blood supply. All reconstructions were successful and the wounds healed properly. None of the patients required reoperation, there were no postoperative complications or surgical site infections.Conclusion: The use of ICG in breast reconstruction with an LD flap is an important predictor of postoperative complications, especially flap necrosis and loss of reconstruction.

Intravoxel incoherent motion as a surrogate marker of perfused vascular density in rat brain.

Intravoxel incoherent motion (IVIM) MRI has emerged as a valuable technique for the assessment of tissue characteristics and perfusion. However, there is limited knowledge about the relationship between IVIM-derived measures and changes at the level of the vascular network. In this study, we investigated the potential use of IVIM MRI as a noninvasive tool for measuring changes in cerebral vascular density. Variations in quantitative immunohistochemical measurements of the vascular density across different regions in the rat brain (cortex, corpus callosum, hippocampus, thalamus, and hypothalamus) were related to the pseudo-diffusion coefficient D* and the flowing blood fraction f in healthy Wistar rats. We assessed whether region-wise differences in the vascular density are reflected by variations in the IVIM measurements and found a significant positive relationship with the pseudo-diffusion coefficient (p < 0.05, β = 0.24). The effect of cerebrovascular alterations, such as blood-brain barrier (BBB) disruption on the perfusion-related IVIM parameters, is not well understood. Therefore, we investigated the effect of BBB disruption on the IVIM measures in a rat model of metabolic and vascular comorbidities (ZSF1 obese rat) and assessed whether this affects the relationship between the cerebral vascular density and the noninvasive IVIM measurements. We observed increased vascular permeability without detecting any differences in diffusivity, suggesting that BBB leakage is present before changes in the tissue integrity. We observed no significant difference in the relationship between cerebral vascular density and the IVIM measurements in our model of comorbidities compared with healthy normotensive rats.

3D Single Vessel Fractional Moving Blood Volume (3D-svFMBV): Fully Automated Tissue Perfusion Estimation Using Ultrasound.

Power Doppler ultrasound (PD-US) is the ideal modality to assess tissue perfusion as it is cheap, patient-friendly and does not require ionizing radiation. However, meaningful inter-patient comparison only occurs if differences in tissue-attenuation are corrected for. This can be done by standardizing the PD-US signal to a blood vessel assumed to have 100% vascularity. The original method to do this is called fractional moving blood volume (FMBV). We describe a novel, fully-automated method combining image processing, numerical modelling, and deep learning to estimate three-dimensional single vessel fractional moving blood volume (3D-svFMBV). We map the PD signals to a characteristic intensity profile within a single large vessel to define the standardization value at the high shear vessel margins. This removes the need for mathematical correction for background signal which can introduce error. The 3D-svFMBV was first tested on synthetic images generated using the characteristics of uterine artery and physiological ultrasound noise levels, demonstrating prediction of standardization value close to the theoretical ideal. Clinical utility was explored using 143 first-trimester placental ultrasound volumes. More biologically plausible perfusion estimates were obtained, showing improved prediction of pre-eclampsia compared with those generated with the semi-automated original 3D-FMBV technique. The proposed 3D-svFMBV method overcomes the limitations of the original technique to provide accurate and robust placental perfusion estimation. This not only has the potential to provide an early pregnancy screening tool but may also be used to assess perfusion of different organs and tumors.

Measuring the Level of Agreement for Lactate Measurements in Hispaniolan Amazon Parrots (Amazona ventralis) Among 2 Point-of-Care Analyzers and a Benchtop Analyzer.

Lactate is an important biochemistry analyte used in human and veterinary medicine to assess tissue perfusion and can be used as a prognostic indicator for certain disease conditions. Whereas lactate is commonly measured using "patient-side" handheld meters, these meters have not been validated for companion avian species. The purpose of this study was to measure the level of agreement between 2 commercially available point-of-care lactate meters and a laboratory benchtop blood analyzer in Hispaniolan Amazon parrots (Amazona ventralis). Blood samples were collected from 20 adult parrots at Louisiana State University by drawing 1.5 mL of blood from the right jugular vein. One drop of whole blood was used for the Lactate Plus analyzer and the remainder of the sample transferred into a lithium heparin microtainer. From the blood in the microtainer, 0.2 mL whole blood was analyzed using the epoc Blood Analysis System, and the remaining sample was centrifuged to obtain plasma that was immediately frozen at -80°C (-112°F) and submitted to the Texas A&M University Clinical Pathology Laboratory for analysis on the VITROS 4500 benchtop analyzer. Bland-Altman agreement plots and Passing-Bablok regression were used to measure the level of agreement between the methods. There was poor agreement between all 3 methods with mean percentage differences in lactate concentrations ≥22% (epoc and Lactate Plus: 33.6% [95% CI: 27-40]; epoc and VITROS 4500: 55% [95% CI:52-58]; VITROS 4500 and Lactate Plus: 22% [95% CI:16-28]). Based on these results, the point-of-care meters tested in this study are not interchangeable, and separate reference intervals were calculated for each method. Blood lactate concentrations may have more utility in tracing lactate trends over time in an individual rather than being able to utilize this information at 1 time point for disease diagnosis and prognosis.

Venous-to-arterial carbon-dioxide tension difference as a useful predictor of patient prognosis after major surgery

PurposeChange in venous-to-arterial carbon dioxide partial pressure difference[P(v-a)CO2] could be a useful marker to assess tissue perfusion status. Herein, we assessed the predictive values of postoperative P(v-a)CO2 measurements for mortality in critically ill patients after major surgery. The correlation between P(v-a)CO2 values and other conventional parameters of patient prognosis was also evaluated. MethodsPatients admitted to the intensive care unit(ICU) after abdominal surgery were enrolled. Arterial and venous blood gas analyses were performed within 1 h(T0) and after 24 h(T1) of admission to the ICU, respectively. The relationship between P(v-a)CO2 levels at T1 and other conventional parameters were assessed using a Bland-Altman plot. Logistic regression analysis was performed to examine the predisposing factors of mortality after surgery. ResultsA total of 231 patients were finally analyzed. We divided the participants into the high PvaCO2 group[P(v-a)CO2 ≥ 8.6] and the low PvaCO2 group[P(v-a)CO2 < 8.6]. Seven-day-, 28-day, and in-hospital mortality were significantly higher in the high PvaCO2 group than in the low PvaCO2 group. There was significant agreement between P(v-a)CO2 values at T1 and APACHE II scores, lactate levels at T1 and total SOFA scores at T1. In multivariate logistic analysis, an increased P(v-a)CO2 value at T1 was the only significant risk factor of 7-day mortality after surgery. [odds ratio:1.341, 95%confidence interval: 1.050–1.714, p=0.019]. ConclusionP(v-a)CO2 measurements could be not only a significant predictor of postoperative prognosis, but also a useful surveillance parameter to maintain tissue perfusion after abdominal surgery in patients with a potential risk of fatal complication-related tissue hypoperfusion.

Prospects of qualitative and quantitative assessment of bowel perfusion by fluorescent angiography with indocyanine green in colorectal surgery. First experience

To assess the possibilities of fluorescent detection system in qualitative and quantitative assessment of bowel perfusion in colorectal resections. From May to August 2023, a single-center pilot cross-sectional unblinded study with inclusion of 18 patients with colon cancer (of left-sided - 12, of right-sided - 6, mean age - 72.9 years, m/w - 61/39%) was conducted. All patients underwent laparoscopic colorectal resections with extracorporeal stage of bowel transection. The evaluation of the bowel's ICG perfusion was conducted to assist in decision making about the level of its resection. Qualitative (visual) assessment was carried out in all 18 patients, in one patient twice, quantitative assessment of perfusion was conducted in 8 patients (left-sided resections - 6, right-sided hemicolectomy - 2). The qualitative evaluation was performed in real time on the analysis of the color gradient. The time parameters and fluorescence intensity at different level proximally and distally from the resection line were quantitatively estimated: Tstart - time of occurrence of minimal fluorescence in the areas of interest after the ICG injection (sec); Tmax - time to achieve maximum fluorescence intensity after the ICG injection (sec); Tmax-start - time interval between Tstart and Tmax, Imax - level of maximum fluorescence intensity (I). Visual qualitative analysis of fluorescence revealed unsatisfactory perfusion characteristics (black, dark-gray color) in the area planned by the surgeon to anastomose the bowel in 3 of 18 patients (16.6%). When analyzing the quantitative data of this group of patients, there was a 2-6-fold decrease in Imax level, and one patient had an increase in Tmax-start at the level of intended resection compared to the bowel's sections in the favorable zone. In all cases, the final bowel transection was conducted in the area of good perfusion. There was no clinical evidence of anastomotic dehiscence in the study group. Intraoperative evaluation of bowel perfusion is an important component of safe anastomosis formation in colorectal surgery. The use of ICG-FA allows to conduct qualitative and quantitative assessment of tissue perfusion of the bowel in order to assist in making intraoperative decisions. Quantitative evaluation of fluorescence provides more objective information about perfusion parameters. Imax and Tmax-start are the most promising quantitative indicators of local bowel's perfusion. Nevertheless, the precise interpretation of the quantitative indicators of ICG perfusion needs to be clarified.

Functional assessment of brain development in fetuses that subsequently deliver very preterm: An MRI pilot study.

To evaluate changes occurring in the fetal brain prior to very preterm delivery using MRI T2* relaxometry, an indirect assessment of tissue perfusion. Fetuses that subsequently delivered spontaneously <32weeks gestation and a control cohort were identified from pre-existing datasets. Participants had undergone a 3T MRI assessment including T2* relaxometry of the fetal brain using a 2D multi-slice gradient echo single shot echo planar imaging sequence. T2* maps were generated, supratentorial brain tissue was manually segmented and mean T2* values were generated. Groups were compared using quadratic regression. Twenty five fetuses that subsequently delivered <32weeks and 67 that delivered at term were included. Mean gestation at MRI was 24.5weeks (SD 3.3) and 25.4weeks (SD 3.1) and gestation at delivery 25.5weeks (SD 3.4) and 39.7weeks (SD 1.2) in the preterm and term cohorts respectively. Brain mean T2* values were significantly lower in fetuses that subsequently delivered before 32weeks gestation (p<0.001). Alterations in brain maturation appear to occur prior to preterm delivery. Further work is required to explore these associations, but these findings suggest a potential window for therapeutic neuroprotective agents in fetuses at high risk of preterm delivery in the future.

IBC-Oxford University2023_BJSOral_18The Use of Indocyanine Green (ICG) Fluorescence Angiography in Laparoscopic Roux-en-Y Gastric Bypass for Perfusion Assessment and Structure Visualisation

Abstract Introduction Indocyanine green (ICG) fluorescence angiography (FA) has been utilised in bariatric surgery for assessment of tissue perfusion and blood supply in laparoscopic sleeve gastrectomy (LSG). However, there is limited literature on its use in laparoscopic Roux-en-Y gastric bypass (LRYGB). The aim of this study was to evaluate the use of ICG-FA in LRYGB for qualitative assessment of tissue perfusion and structure identification. These are the first cases utilising ICG-FA in LRYGB to be performed in the United Kingdom. Methods Thirty-five patients (12 male, 34%, 23 females, 66%) with median (IQR) age of 45 (38 – 52) years and preoperative median (IQR) BMI 45 (37 – 49) kg/m2 underwent LRYGB with ICG-FA. ICG was administered intravenously according to an agreed protocol. Karl Storz® Image 1 Rubina system with overlay and monochromatic modes was utilised for perfusion assessment. ICGFA was utilised for qualitative assessment of gastric pouch perfusion before and after linear stapled gastro-jejunal anastomosis and visualisation of key anatomical landmarks. The perfusion pattern was assessed by the operating team based on a ICG scoring system (ICG-S), which ranged from 1 (no perfusion) to 4 (excellent perfusion) based on timing following ICG injection and intensity of fluorescence detected in the anatomical structures. Results From April 2021 to August 2022, 34 patients underwent primary LRYGB with use of ICG- FA. ICG was utilised in one revisional case. No adverse effects to ICG were observed. ICG-S was 4 in 33 patients. (94%). In two patients (6%), operative strategy was modified based on focal area of no perfusion (ICG score 1) in gastric pouch. ICG-FA helped improve operative safety during division of omentum and in recognition of duodeno-jejunal flexure with fluorescence detection in epiploic vessels and inferior mesenteric vein (IMV) respectively. There were no leaks at a median follow up of 9 months. Conclusion ICGFA imaging allows for qualitative assessment of perfusion and identification of critical anatomical landmarks during LRYGB. The technology is safe and its utilisation in LRYGB provides a “real-time image” of gastric pouch perfusion, helping to demonstrate ischaemic or poorly perfused areas with an opportunity to modify operative strategy.

Dual-Scan Photoacoustic Tomography for the Imaging of Vascular Structure on Foot.

Chronic leg ulcers are affecting approximately 6.5 million Americans, and they are associated with significant mortality, reduced quality of life, and high treatment costs. Since many chronic ulcers have underlying vascular insufficiency, accurate assessment of tissue perfusion is critical to treatment planning and monitoring. This study introduces a dual-scan photoacoustic (PA) tomography (PAT) system that can simultaneously image the dorsal and plantar sides of the foot to reduce imaging time. To account for the unique shape of the foot, the system employs height-adjustable and articulating baseball stages that can scan along the foot's contour. In vivo results from healthy volunteers demonstrate the system's ability to acquire clear images of foot vasculature, and results from patients indicate that the system can image patients with various ulcer conditions. We also investigated various PA features and examined their correlation with the foot condition. Our preliminary results indicate that vessel sharpness, occupancy, intensity, and density could all be used to assess tissue perfusion. This research demonstrated the potential of PAT for routine clinical tissue perfusion assessment.

Indocyanine Green in Bariatric Surgery: a Systematic Review.

Indocyanine green (ICG) is a fluorescent dye that can be used intraoperatively to assess tissue perfusion, as well as perform leak testing. This study aims to summarize published manuscripts on outcomes of ICG use and reduction of complications compared to traditional leak test and tissue perfusion evaluation. A PubMed search using "ICG and bariatric surgery," "ICG and gastric sleeve," "ICG and gastric bypass," and "ICG and revisional bariatric surgery" was performed. The proportion of patients who underwent an intraoperative decision change due to ICG was 3.8% (95% CI: 2.0 to 7.2%). ICG fluorescent imaging in bariatric surgery is a valuable tool, and further studies are needed to confirm its utility for routine use in both standard or complex cases (PROSPERO #418126).

Central venous-to-arterial CO2 difference as a biomarker of outcome in children who underwent surgery for congenital heart disease.

In congenital heart surgery, low cardiac output syndrome (LCOS) is a major cause of morbidity in the immediate post-operative period. A decrease in cardiac output leads to an increase in tissue oxygen consumption. Several biomarkers such as venous oxygen saturation (SvO2), arteriovenous oxygen difference (DavO2), and lactate can assess tissue perfusion in the presence of LCOS. Recently, central venous to arterial CO2 difference (ΔCO2) has been proposed as a biomarker of tissue ischemia that could be used as a predictor of death in neonatal patients. This study aimed to analyze the relationship between ΔCO2 and immediate post-operative outcomes in pediatric patients undergoing congenital heart surgery and its correlation with DavO2, SvO2, and lactate. We conducted a longitudinal study of patients aged 0-18 years who underwent congenital heart surgery with or without cardiopulmonary bypass at the Instituto Nacional de Pediatría, from March 2019 to March 2021. Eighty-two patients were included; the median age was 17 months. About 59% had a ΔCO2 ≥ 6 mmHg. Patients with ΔCO2 ≥ 6 mmHg had a vasoactive-inotropic score > 5 (p < 0.001), DavO2 > 5 mL/dL (p = 0.048), and lactate > 2 mmol/L (p = 0.027), as well as a longer hospital stay (p = 0.043). Patients with ΔCO2 > 6 mmHg and vasoactive-inotropic score ≥ 10 were 12.6 times more likely to die. ΔCO2 is a good marker of tissue hypoperfusion and outcome in the post-operative period of congenital heart surgery.

Cardiovascular Applications of Photon-Counting CT Technology: A Revolutionary New Diagnostic Step.

Photon-counting computed tomography (PCCT) is an emerging technology that can potentially transform clinical CT imaging. After a brief description of the PCCT technology, this review summarizes its main advantages over conventional CT: improved spatial resolution, improved signal and contrast behavior, reduced electronic noise and artifacts, decreased radiation dose, and multi-energy capability with improved material discrimination. Moreover, by providing an overview of the existing literature, this review highlights how the PCCT benefits have been harnessed to enhance and broaden the diagnostic capabilities of CT for cardiovascular applications, including the detection of coronary artery calcifications, evaluation of coronary plaque extent and composition, evaluation of coronary stents, and assessment of myocardial tissue characteristics and perfusion.

Combined evaluation of blood flow and tissue perfusion in diabetic feet by intra-arterial dynamic 4DCT imaging

Critical limb ischemia is associated with high mortality and major amputations. Intra-arterial digital subtraction angiography (IADSA) has been the reference standard but has some shortcomings including the two-dimensional projection and the lack of tissue perfusion information. The aim of this exploratory study is to examine four-dimensional computed tomography (4DCT) angiography and perfusion imaging using low-volume intra-arterial contrast injections for an improved anatomic and hemodynamic assessment in patients with foot ulcers. Three patients underwent a low-volume (2 mL) intra-arterial contrast-enhanced 4DCT examination combined with a diagnostic IADSA. An automated assessment of blood flow and tissue perfusion from the 4DCT data was performed. Vascular structures and corresponding blood flows were successfully assessed and correlated well with the IADSA results. Perfusion values of the affected tissue were significantly higher compared to the unaffected tissue. The proposed 4DCT protocol combined with the minimal usage of contrast agent (2 mL) provides superior images compared to IADSA as three phases (arterial, perfusion, and venous) are captured. The obtained parameters could allow for an improved diagnosis of critical limb ischemia as both the proximal vasculature and the extent of the perfusion deficit in the microvasculature can be assessed.Relevance statementIntra-arterial 4DCT allows for assessing three phases (arterial, perfusion and venous) using minimal contrast (2 mL). This method could lead to an improved diagnosis of critical limb ischemia as both proximal vasculature and the extent of the perfusion deficit are assessed.Trial registrationISRCTN, ISRCTN95737449. Registered 14 March 2023—retrospectively registered, https://www.isrctn.com/ISRCTN95737449Key points• Three phases (arterial, perfusion, and venous) are obtained from 2 mL intra-arterial 4DCT.• The obtained hemodynamic parameters correlated well with the IADSA findings.• 4DCT surpassed IADSA in terms of assessment of venous blood flow and inflammatory hyperperfusion.• The assessment of tissue perfusion could lead to optimizing the revascularization strategy.Graphical

Intraoperative ICG-Fluorescence as a Method to Prevent Postoperative Strictures of Uretero-Ileal Anastomoses in Robot-Assisted Radical Cystectomy

Introduction. Radical cystectomy with urine diversion is recognized as the standard for the treatment of muscle-invasive bladder cancer. One of the dangerous complications in the postoperative period is the stricture of uretero-ileal anastomosis leading to hydroureteronephrosis, renal failure, and urosepsis. One of the factors in the development of the anastomotic stricture is ischemia. In order to reduce possible ischemic injury, the following manipulations are performed: careful treatment of tissues in the area of future anastomosis, preservation of periureteral adventitia, minimal mobilization of ureters before implantation into conduit. Intraoperative assessment of ureteral and intestinal tissue perfusion using ICG-fluorescence is a promising area. Materials and methods. The study enrolled 56 patients who underwent a robotic-assisted radical cystectomy with intracorporeal urine diversion from January 2021 to March 2022 at the Bashkir State Medical University Clinic. Patients were divided into two groups: group 1 (22 patients) underwent intraoperative ICG-imaging, and group 2 (34 patients) — imaging without fluorescence. The median follow-up period was 14 months for group 1 and 12 months for group 2. The comparison criteria between the groups were demographic indicators, perioperative outcomes (including 30- and 90-day complications), and the incidence of strictures of uretero-ileal anastomoses. The groups were compared using a test for equality of means and a test for sampling distributions. Results and discussion. No statistically significant differences between patients were reported during the time of surgery, estimated blood loss, and duration of hospital stay. No significant differences were also detected in the incidence of 30- and 90-day complications and the number of readmissions among patients in group 1 and group 2 (p = 0.477 and p = 0.089, respectively). The incidence of strictures of uretero-ileal anastomosis in group 1 demonstrated a statistically significant decrease, as compared with group 2 (0/34 [0 %] and 7/68 [10.3 %], p = 0.020). Conclusion. The ICG-fluorescence imaging to assess vascularization of the distal ureter during robotic-assisted radical cystectomy with intracorporeal urine diversion may reduce the risk of postoperative uretero-ileal anastomotic ischemic strictures.

The impact of using the internal mammary artery as a recipient vessel on medial mastectomy skin flap perfusion in autologous breast reconstruction: An observational study using indocyanine green

The internal mammary artery (IMA) is the preferred recipient vessel for microvascular anastomosis in immediate autologous breast reconstruction following skin-sparing mastectomy (SSM). Although the IMA accounts for approximately 60% of the blood supply to the breast, the exact contribution to the mastectomy skin flap perfusion is unclear. The aim of this observational study was to investigate the impact of using the IMA as a recipient vessel on medial mastectomy skin flap perfusion assessed with indocyanine green angiography (ICGA). This observational study included ten consecutive women who underwent immediate autologous breast reconstructions following SSM. Two intraoperative indocyanine green (ICG) assessments were performed to assess tissue perfusion of the upper and lower part of the medial mastectomy skin flap: the first following the SSM and the second after clamping the IMA. During a 120-second angiography, three additional images were made after 60, 90, and 120s. The ICG inflow time and mean, minimum, and maximum fluorescence intensities (FIs) were obtained. Four unilateral and six bilateral autologous breast reconstructions were included. There was no difference in tissue perfusion when comparing the inflow time (24.1s vs. 23.0s, P=0.348), the mean FI (131.4 vs. 124.0, P=0.126), minimum FI (28.6 vs. 33.4, P=0.086), and maximum FI (253.1 vs. 247.6, P=0.166) before and after clamping the IMA. According to this study, the use of the IMA as a recipient vessel does not reduce medial mastectomy skin flap perfusion in patients undergoing immediate autologous breast reconstructions following SSM.

К ПРОБЛЕМЕ ДИАГНОСТИКИ В ПРЕВЕНТИВНОЙ ЭНДОДОНТИИ

Subject. The most significant problem of modern preventive endodontics is to determine the vitality of the pulp and, accordingly, to make a decision about the choice of treatment method. The early stages of inflammation in the pulp may not be fully detected clinically and require the inclusion of additional examination methods that assess the state of microcirculation in the neurovascular bundle, as well as the severity of the immune response. These methods include: clinical and immunological examination of the gingival fluid (GF), as well as the assessment of tissue perfusion using laser Doppler flowmetry (LDF). &#x0D; Objectives. The purpose of the study is to optimize the diagnostics of the dental pulp condition in the context of implementing the concept of preventive endodontics.&#x0D; Methodology. 37 patients aged 19–29 years with a diagnosis of K 04.00 "Pulp hyperemia" were examined. In addition to the basic methods of examination, LDF and immunological study of GF (IL-1β, TNF-α, IL-4) were used. In each patient, 1 tooth with pulp hyperemia and 1 intact (control) tooth were examined.&#x0D; Results. In the immunological analysis of DF in the area of teeth with pulp hyperemia, higher values of cytokines were obtained compared to intact teeth (p &lt; 0.05). At the same time, in the area of 2 teeth with pulp hyperemia (5.4%), the level of cytokines was higher than their average values in the group of carious teeth. LDF of teeth with pulpal hyperemia also revealed higher values of M and σ compared with similar parameters in control teeth (p &lt; 0.05). At the same time, in 2 cases, the highest levels of LDF were noted, which was consistent with the previously observed high values of cytokines in the gingival fluid in these loci. Moreover, after 2 weeks, a clinic of irreversible pulpitis was observed in these 2 teeth.&#x0D; Conclusion. When diagnosing reversible forms of pulpitis and deciding on the possibility of biological treatment of pulp hyperemia, it is necessary to assess the state of microcirculatory changes that have occurred in the pulp tissue, as well as the level of local immunological reactions.

Use of CO2-Derived Variables in Cardiac Intensive Care Unit: Pathophysiology and Clinical Implications.

Shock is a life-threatening condition, and its timely recognition is essential for adequate management. Pediatric patients with congenital heart disease admitted to a cardiac intensive care unit (CICU) after surgical corrections are particularly at risk of low cardiac output syndrome (LCOS) and shock. Blood lactate levels and venous oxygen saturation (ScVO2) are usually used as shock biomarkers to monitor the efficacy of resuscitation efforts, but they are plagued by some limitations. Carbon dioxide (CO2)-derived parameters, namely veno-arterial CO2 difference (ΔCCO2) and the VCO2/VO2 ratio, may represent a potentially valuable addition as sensitive biomarkers to assess tissue perfusion and cellular oxygenation and may represent a valuable addition in shock monitoring. These variables have been mostly studied in the adult population, with a strong association between ΔCCO2 or VCO2/VO2 ratio and mortality. In children, particularly in CICU, few studies looked at these parameters, while they reported promising results on the use of CO2-derived indices for patients' management after cardiac surgeries. This review focuses on the physiological and pathophysiological determinants of ΔCCO2 and VCO2/VO2 ratio while summarizing the actual state of knowledge on the use of CO2-derived indices as hemodynamical markers in CICU.

Cardiovascular Magnetic Resonance Imaging as an Adjunct to the Evaluation of Cardiovascular Involvement in Diabetes Mellitus.

Diabetes mellitus (DM) is a new epidemic which has presented an immense increase in recent decades, due to the rapid increase in obesity. Cardiovascular disease (CVD) significantly reduces life expectancy and is the main cause of death in type 2 diabetes mellitus (T2DM). Strict glycemic control is a well-established method to combat microvascular CVD of type 1 diabetes mellitus (T1DM); its role against CVD of the T2DM risk has not been well documented. Therefore, the most efficient prevention is multifactorial risk factor reduction. Recently, the European Society of Cardiology published its 2019 recommendations on CVD in DM. Although all clinical points were discussed in this document, only a few comments were presented about when and how we should recommend cardiovascular (CV) imaging. Currently, CV imaging is the "must" in CV noninvasive evaluation. Alterations in CV imaging parameters can lead to early recognition of various types of CVD. In this paper, we briefly discuss the role of noninvasive imaging modalities, emphasizing the benefits of including cardiovascular magnetic resonance (CMR) in the evaluation of DM. CMR, in the same examination, can provide an assessment of tissue characterization, perfusion and function, with excellent reproducibility and without radiation or limitations, due to the body habitus. Therefore, it can play a dominant role in the prevention and risk stratification of DM. The suggested protocol for DM evaluation should include routine annual echocardiographic evaluation of all DM patients and CMR assessment of those with poorly controlled DM, microalbuminuria, heart failure, arrhythmia and recent alterations in clinical or echocardiographic evaluation.