Microcirculatory Alterations Research Articles

Quantitative Evaluation of Microcirculatory Alterations in Patients with COVID-19 and Bacterial Septic Shock through Remote Photoplethysmography and Automated Capillary Refill Time Analysis.

Background and Objectives: Sepsis, a leading global health challenge, accounts for around 20% of deaths worldwide. The complexity of sepsis, especially the difference between bacterial and viral etiologies, requires an effective assessment of microcirculation during resuscitation. This study aimed to evaluate the impact of infusion therapy on microcirculation in patients with sepsis, focusing on bacterial- and COVID-19-associated sepsis using remote photoplethysmography (rPPG) and the automated capillary refill time (aCRT). Materials and Methods: This single-center prospective study was conducted in the ICU of Pauls Stradins Clinical University Hospital, including 20 patients with sepsis/septic shock. The patients were selected based on hemodynamic instability and divided into COVID-19 and Bacterial Septic Shock groups. Fluid responsiveness was assessed using the Passive Leg Raising Test (PLRT). Systemic hemodynamics and microcirculation were monitored through MAP CRT, rPPG, and serum lactate levels. Statistical analyses compared responses within and between the groups across different stages of the protocol. Results: The Bacterial group exhibited higher initial serum lactate levels and more pronounced microcirculatory dysfunction than the COVID-19 group. rPPG was more sensitive in detecting perfusion changes, showing significant differences between the groups. The automated CRT demonstrated greater sensitivity compared to the manual CRT, revealing significant differences during PLRT stages between bacterial- and COVID-19-associated sepsis. Both groups had a transient hemodynamic response to PLRT, with subsequent stabilization upon fluid infusion. Conclusions: When managing patients with sepsis in intensive care, monitoring microcirculation is of paramount importance in infusion therapy. Our study highlights the potential of rPPG and aCRT as tools for this purpose. These techniques can be used in conjunction with routine parameters, such as lactate levels and systemic hemodynamic parameters, to provide a comprehensive assessment of a patient's condition.

Retinal microcirculation changes in prediabetic patients with short-term increased blood glucose using optical coherence tomography angiography.

Retinal microcirculation alterations are early indicators of diabetic microvascular complications. Optical coherence tomography angiography (OCTA) is a noninvasive method to assess these changes. This study analyzes changes in retinal microcirculation in prediabetic patients during short-term increases in blood glucose using OCTA. To investigate the changes in retinal microcirculation in prediabetic patients experiencing short-term increases in blood glucose levels using OCTA. Fifty volunteers were divided into three groups: Group 1 [impaired fasting glucose (IFG) or impaired glucose tolerance (IGT)], Group 2 (both IFG and IGT), and a control group. Retinal microcirculation parameters, including vessel density (VD), perfusion density (PD), and foveal avascular zone (FAZ) metrics, were measured using OCTA. Correlations between these parameters and blood glucose levels were analyzed in both the fasting and postprandial states. One hour after glucose intake, the central VD (P = 0.023), central PD (P = 0.026), and parafoveal PD (P < 0.001) were significantly greater in the control group than in the fasting group. In Group 1, parafoveal PD (P < 0.001) and FAZ circularity (P = 0.023) also increased one hour after glucose intake. However, no significant changes were observed in the retinal microcirculation parameters of Group 2 before or after glucose intake (P > 0.05). Compared with the control group, Group 1 had a larger FAZ area (P = 0.032) and perimeter (P = 0.018), whereas Group 2 had no significant differences in retinal microcirculation parameters compared with the control group (P > 0.05). Compared with Group 1, Group 2 had greater central VD (P = 0.013) and PD (P = 0.008) and a smaller FAZ area (P = 0.012) and perimeter (P = 0.010). One hour after glucose intake, Group 1 had a larger FAZ area (P = 0.044) and perimeter (P = 0.038) than did the control group, whereas Group 2 showed no significant differences in retinal microcirculation parameters compared with the control group (P > 0.05). Group 2 had greater central VD (P = 0.042) and PD (P = 0.022) and a smaller FAZ area (P = 0.015) and perimeter (P = 0.016) than Group 1. At fasting, central PD was significantly positively correlated with blood glucose levels (P = 0.044), whereas no significant correlations were found between blood glucose levels and OCTA parameters one hour after glucose intake. A short-term increase in blood glucose has a more pronounced effect on retinal microcirculation in prediabetic patients with either IFG or IGT.

Alterations in Regional Brain Microcirculation in Patients with Sepsis: A Prospective Study Using Contrast-Enhanced Brain Ultrasound.

Alterations in regional brain microcirculation have not been well studied in patients with sepsis. Regional brain microcirculation can be studied using contrast-enhanced brain ultrasound (CEUS) with microbubble administration. CEUS was used to assess alterations in regional brain microcirculation on 3 consecutive days in 58 patients with sepsis and within 24h of intensive care unit admission in 10 aged-matched nonseptic postoperative patients. Time-intensity perfusion curve variables (time-to-peak and peak intensity) were measured in different regions of interest of the brain parenchyma. The mean arterial pressure, cardiac index (using transthoracic echocardiography), global cerebral blood flow (using echo-color Doppler of the carotid and vertebral arteries), mean flow velocities of the middle cerebral arteries, and brain autoregulation (using transcranial echo-color Doppler) were measured simultaneously. The presence of structural brain injury in patients with sepsis was confirmed on computed tomography imaging, and encephalopathy, including coma and delirium, was evaluated using the Glasgow Coma Scale and the Confusion Assessment Method in the Intensive Care Unit. Of the 58 patients with sepsis, 42 (72%) developed acute encephalopathy and 11 (19%) had some form of structural brain injury. Brain autoregulation was impaired in 23 (40%) of the patients with sepsis. Brain microcirculation alterations were observed in the left lentiform nucleus and left white matter of the temporoparietal region of the middle cerebral artery in the sepsis nonsurvivors but not in the survivors or postoperative patients. The alterations were characterized by prolonged time-to-peak (p < 0.01) and decreased peak intensity (p < 0.01) on the time-intensity perfusion curve. Prolonged time-to-peak but not decreased peak intensity was independently associated with worse outcome (p = 0.03) but not with the development of encephalopathy (p = 0.77). Alterations in regional brain microcirculation are present in critically ill patients with sepsis and are associated with poor outcome. Trial registration Registered retrospectively on December 19, 2019.

Genetic Algorithms for Feature Selection in the Classification of COVID-19 Patients.

Severe Acute Respiratory Syndrome CoronaVirus-2 (SARS-CoV-2) infection can cause feared consequences, such as affecting microcirculatory activity. The combined use of HRV analysis, genetic algorithms, and machine learning classifiers can be helpful in better understanding the characteristics of microcirculation that are mainly affected by COVID-19 infection. This study aimed to verify the presence of microcirculation alterations in patients with COVID-19 infection, performing Heart Rate Variability (HRV) parameters analysis extracted from PhotoPlethysmoGraphy (PPG) signals. The dataset included 97 subjects divided into two groups: healthy (50 subjects) and patients affected by mild-severity COVID-19 (47 subjects). A total of 26 parameters were extracted by the HRV analysis and were investigated using genetic algorithms with three different subject selection methods and five different machine learning classifiers. Three parameters: meanRR, alpha1, and sd2/sd1 were considered significant, combining the results obtained by the genetic algorithm. Finally, machine learning classifications were performed by training classifiers with only those three features. The best result was achieved by the binary Decision Tree classifier, achieving accuracy of 82%, specificity (or precision) of 86%, and sensitivity of 79%. The study's results highlight the ability to use HRV parameters extraction from PPG signals, combined with genetic algorithms and machine learning classifiers, to determine which features are most helpful in discriminating between healthy and mild-severity COVID-19-affected subjects.

Dexmedetomidine Improves Microcirculatory Alterations in Patients With Initial Resuscitated Septic Shock.

The study was to investigate the effects of dexmedetomidine on microcirculation in patients with early septic shock despite initial resuscitation. This was a single-center prospective study. Patients with early septic shock despite initial fluid resuscitation who still required norepinephrine to maintain target arterial pressure were enrolled. Hemodynamic and gas analysis variables, sublingual microcirculatory parameters were measured at baseline, and during the infusion of dexmedetomidine for 1 h (0.7mcg/kg/h). To elucidate the possible mechanisms of the effect of dexmedetomidine on microcirculation, after interim analysis, the dose-effect relationship of dexmedetomidine on microcirculation and catecholamine level were investigated at baseline, 1h after stabilization at different doses of dexmedetomidine (0.7 and 0.3 mcg/kg/h), and 2h after dexmedetomidine cessation. Forty-four patients with septic shock were enrolled after initial resuscitation. Compared with baseline, total and perfused vascular densities were statistically increased after infusion of dexmedetomidine, which was correlated with the dose of dexmedetomidine. During dexmedetomidine infusion, plasma norepinephrine, and dopamine level were significantly decreased. Changes in plasma norepinephrine level contributed to dexmedetomidine infusion were well correlated with changes in total and perfused vascular densities. In adult patients with resuscitated septic shock, dexmedetomidine improved microcirculation, which might be associated with plasma catecholamine level. However, double-blinded large sample studies should be performed to verify the results.

Retinal microvascular changes in patients with pancreatitis and their clinical significance

Acute pancreatitis, a common exocrine inflammatory disease affecting the pancreas, is characterized by intense abdominal pain and multiple organ dysfunction. However, the alterations in retinal blood vessels among individuals with acute pancreatitis remain poorly understood. This study employed optical coherence tomography angiography (OCTA) to examine the superficial and deep retinal blood vessels in patients with pancreatitis. Sixteen patients diagnosed with pancreatitis (32 eyes) and 16 healthy controls (32 eyes) were recruited from the First Affiliated Hospital of Nanchang University for participation in the study. Various ophthalmic parameters, such as visual acuity, intraocular pressure, and OCTA image for retina consisting of the superficial retinal layer (SRL) and the deep retinal layer (DRL), were recorded for each eye. The study observed the superficial and deep retinal microvascular ring (MIR), macrovascular ring (MAR), and total microvessels (TMI) were observed. Changes in retinal vascular density in the macula through annular partitioning (C1–C6), hemispheric quadrant partitioning (SR, SL, IL, and IR), and early diabetic retinopathy treatment studies (ETDRS) partitioning methods (R, S, L, and I). Correlation analysis was employed to investigate the relationship between retinal capillary density and clinical indicators. Our study revealed that in the superficial retinal layer, the vascular density of TMI, MIR, MAR, SR, IR, S, C2, C3 regions were significantly decreased in patients group compared with the normal group. For the deep retinal layer, the vascular density of MIR, SR, S, C1, C2 regions also reduced in patient group. The ROC analysis demonstrated that OCTA possesses significant diagnostic performance for pancreatitis. In conclusion, patients with pancreatitis may have retinal microvascular dysfunction, and OCTA can be a valuable tool for detecting alterations in ocular microcirculation in pancreatitis patients in clinical practice.

Transitions from Aerobic to Anaerobic Metabolism and Oxygen Debt during Elective Major and Emergency Non-Cardiac Surgery.

Intraoperative hemodynamic and metabolic optimization of both the high-risk surgical patients and critically ill patients remains challenging. Reductions in oxygen delivery or increases in oxygen consumption can initiate complex cellular processes precipitating oxygen debt (OXD). This study tested the hypothesis that intraoperative changes in sublingual microcirculatory flow reflect clinically relevant transitions from aerobic to anaerobic metabolism (TRANAM). We included patients undergoing elective major and emergency non-cardiac surgery. Macro- and microcirculatory variables, oxygen extraction, and transitions of metabolism were assessed in both cohorts. In the elective group, OXD was progressively increased over time, with an estimated 2.24 unit increase every 30 min (adjusted p < 0.001). Also, OXD was negatively correlated with central venous pressure (ρ = -0.247, adjusted p = 0.006) and positively correlated with stroke volume variation (ρ = 0.185, adjusted p = 0.041). However, it was not significantly correlated with sublingual microcirculation variables. In the emergency surgery group, OXD increased during the first two intraoperative hours and then gradually decreased until the end of surgery. In that cohort, OXD was positively correlated with diastolic arterial pressure (ρ = 0.338, adjpatients and the critically ill patients remains challengingsted p = 0.015). Also, OXD was negatively correlated with cardiac index (ρ = -0.352, adjusted p = 0.003), Consensus Proportion of Perfused Vessels (PPV) (ρ = -0.438, adjusted p < 0.001), and Consensus PPV (small) (ρ = -0.434, adjusted p < 0.001). TRANAM were evident in both the elective major and emergency non-cardiac surgery cohorts independent of underlying alterations in the sublingual microcirculation.

Ocular blood flow dynamics following sinus rhythm restoration through catheter ablation: laser speckle flowgraphy in patients with persistent atrial fibrillation.

Laser speckle flowgraphy (LSFG) is a well-established tool renowned for its non-invasive and reproducible assessment of ocular blood flow. While rhythm control therapies, such as catheter ablation (CA), have shown promise in enhancing cognitive function in atrial fibrillation (AF) patients, the acute impact of CA on microcirculatory changes, particularly in ocular blood flow, remains a topic of limited understanding. The present study aims to delve into the potential of LSFG in detecting microcirculatory alterations following the restoration of sinus rhythm (SR) through CA in patients with AF. We studied 8 paroxysmal AF (Paf) and 20 persistent AF (PeAF) patients (mean age 67 ± 6 years, 26% female) undergoing CA. Ocular blood flow was assessed using LSFG by measuring the mean blur rate (MBR) pre- and post-CA. Post-CA, all PeAF patients achieved SR restoration, resulting in a significant increase in tissue MBR (10.0 ± 2.2 to 10.8 ± 2.9, P = 0.021). In contrast, Paf patients showed no significant difference between pre- and post-MBR (12.0 ± 2.7 vs. 11.8 ± 2.6, P = 0.76). LSFG analysis effectively identified microcirculatory changes in patients undergoing CA for PeAF, suggesting that therapeutic interventions targeting the heart may have broader implications for ocular and cerebral health, establishing a novel 'cardio-oculo-cerebral relationship'.

Microcirculatory depth of focus measurement shows reduction of tissue edema by albumin resuscitation in burn patients

BackgroundSevere burns induce volume shifts via capillary leaks, eventually requiring massive fluid resuscitation and promoting tissue edema. Albumin may help to mitigate the edema, thereby improving perfusion. This study shows that sublingual microcirculation measurements can quantify both tissue perfusion and edema. MethodsThis prospective observational study was conducted between November 2018 and December 2019 in the intensive care unit of Maasstad Hospital Burn Center, Rotterdam, The Netherlands. Patients with severe burns affecting >15% of the total body surface area were included. Fluid management was conducted in accordance with the Parkland formula. Albumin (20%) was administered at a rate of 0.5 mL/(kg·h), starting 12 h after the burn incident. Alterations in the sublingual microcirculation, including capillary perfusion and density, were measured at admission (T0) and at 4 h (T4) and 12 h (T12) after admission. Sublingual depth of focus (DOF) of the microcirculation was used to quantify the tissue edema. ResultsNine patients were recruited with a mean total body surface area of 36% ± 23%. By T12, a median of 4085 mL (interquartile range [IQR]: 3714–6756 mL) of crystalloids and 446 mL (IQR: 176–700 mL) of 20% albumin were administered. The DOF increased significantly after crystalloid administration (T4 vs. T0, mean difference [MD]=27.4 µm, 95% confidence interval [CI]: 3.4 to 50.9, P=0.040). Following albumin administration, DOF significantly decreased (T12 vs. T4, MD=-76.4 µm, 95% CI: -116.6 to -36.1, P=0.002). Total vessel density decreased significantly with crystalloid administration (T4 vs. T0, MD=-3.5 mm/mm2, 95% CI: -5.7 to -1.4, P=0.004) but increased after albumin administration (T12 vs. T4, MD=6.2 mm/mm2, 95% CI: 3.2 to 9.3, P=0.001). ConclusionSublingual microcirculation measurement of DOF and other parameters provide a valuable tool for the assessment of tissue perfusion and edema in patients with severe burns. Further investigation is required to evaluate the role of albumin in increasing microcirculatory convection and reducing tissue edema.

CORRELATION BETWEEN RETINAL MICROCIRCULATION, ECHOCARDIOGRAPHIC PARAMETERS AND MYOCARDIAL CORONARY FLOW RESERVE

Objective: Arterial hypertension causes cardiac functional and structural alterations. In hypertensive patients without flow-limiting epicardial coronary artery disease, we investigated the possible relationship between retinal microcirculation, positron emission tomography myocardial blood flow (MBF) and echocardiographic parameters of left ventricular (LV) performance, including mechano-energetic efficiency indexed for myocardial mass (MEEi) Design and method: Nineteen hypertensive patients (mean age 65 ± 11, 10 F) without flow-limiting epicardial coronary artery disease underwent patients wall-to-lumen ratio (WLR) and the cross-sectional area of the vascular wall (WCSA) of retinal arterioles by an Adaptive Optics (AO) retinal camera, echocardiography, including MEEi computation, and cardiac 13NH3 positron emission tomography (13NH3 PET) with assessment of myocardial coronary flow reserve (CFR). A positive 13NH3 PET was defined as a ratio of stress (regadenoson) myocardial blood flow (MBF)/mass and resting MBF/mass lower than 2. Results: No significant differences of demographic parameters were observed between patients with positive (n=6) vs negative (n=13) 13NH3 PET. In all patients WLR was significantly related to BMI (0,50, p=0.02), age (r=0.49, p=0.03)and LVMi (r=0.48, p=0.03) at univariate analysis. A negative correlation was also observed between WLR and total CFR (-0.64, p=0.003) and MMEi (-0.35, p=0.13). The relationship between WLR and CFR remained significant after adjustment for age and BMI (r=-0.49, p=0.047). Conclusions: In hypertensive patients without flow-limiting epicardial coronary artery disease, retinal WLR could reflect the presence of structural alterations in coronary microcirculation, possibly contributing to an impairment of CFR and to early LV dysfunction, as detected by low values of MEEi.

Unveiling Lovastatin's Anti-Inflammatory Potential in Mouse's Brain during Acute Trypanosoma cruzi Infection.

Neurological commitment is a neglected manifestation of Chagas disease (CD). Meningoencephalitis mainly affects children and immunosuppressed patients, while stroke can occur with or without cardiac compromise. One of the possible causes of stroke development is microvascular commitment. Our group previously described that experimental Trypanossoma cruzi acute infection leads to cerebral microvasculopathy. This condition is characterized by decreased capillary density, increased leukocyte rolling and adhesion, and endothelial dysfunction. CD was discovered 114 years ago, and until today, only two drugs have been available for clinical treatment: benznidazole and nifurtimox. Both present a high cure rate for the acute phase (80%) and small cure rate for the chronic phase (20%). In addition, the high occurrence of side-effects, without proper medical follow-up, can result in treatment abandonment. Therefore, the search for new therapeutic schemes is necessary. Statins are drugs already used in the clinic that have several pleiotropic effects including endothelial function improvement, anti-inflammatory action, as well as trypanocidal effects, making them a potential alternative treatment for brain microvasculopathy in CD. Here, we investigate the effect of lovastatin (LOV) on brain microvasculopathy and inflammatory parameters. Swiss Webster mice were intraperitoneally inoculated with the Y strain of T. cruzi. Treatment with lovastatin (20 mg/kg/day) was initiated 24 h after the infection and continued for 14 consecutive days. We observed that LOV treatment did not affect parasitemia, brain microcirculation alterations, or the reduction in cerebral blood flow caused by T. cruzi infection. Also, LOV did not prevent the increased number of CD3+ cells and eNOS levels in the T. cruzi-infected brain. No alterations were observed on VCAM-1 and MCP-1 expressions, neither caused by infection nor LOV treatment. However, LOV prevented the increase in F4/80+ cells and ICAM-1 levels in the brain caused by acute infection with T. cruzi. These results suggest an anti-inflammatory activity of LOV, but more studies are needed to elucidate the role of LOV in CD acute infection.

Tissue perfusion monitoring in children with acute circulatory dysfunction: narrative review

Sepsis is one of the main causes of admission to Intensive Care Units (ICU). The hemodynamic objectives usually sought during the resuscitation of the patient in septic shock correspond to macrohemodynamic parameters (heart rate, blood pressure, central venous pressure). However, persistent alterations in microcirculation, despite the restoration of macrohemodynamic parameters, can cause organ failure. This dissociation between the macrocirculation and microcirculation originates the need to evaluate organ tissue perfusion, the most commonly used being urinary output, lactatemia, central venous oxygen saturation (ScvO2), and veno-arterial pCO2 gap. Because peripheral tissues, such as the skin, are sensitive to disturbances in perfusion, noninvasive monitoring of peripheral circulation, such as skin temperature gradient, capillary refill time, mottling score, and peripheral perfusion index may be helpful as early markers of the existence of systemic hemodynamic alterations. Peripheral circulation monitoring techniques are relatively easy to interpret and can be used directly at the patient's bedside. This approach can be quickly applied in the intra- or extra-ICU setting. The objective of this narrative review is to analyze the various existing tissue perfusion markers and to update the evidence that allows guiding hemodynamic support in a more individualized therapy for each patient.

Clinical efficacy of femtosecond laser-assisted phacoemulsification in diabetic cataract patients.

Diabetic patients with cataracts encounter specific difficulties during cataract surgery due to alterations in microcirculation, blood supply, metabolism, and the microenvironment. Traditional phacoemulsification may not fully tackle these issues, especially in instances with substantial preoperative astigmatism. The utilization of femtosecond laser-assisted phacoemulsification, in conjunction with Toric intraocular lens (IOL) implantation, offers a potentially more efficient strategy. This research seeks to evaluate the efficacy and possible complications of this approach in diabetic cataract patients. To investigate the clinical efficacy and complications of femtosecond laser-assisted phacoemulsification combined with Toric IOL implantation in diabetic cataract patients, comparing it with traditional phacoemulsification methods. This retrospective study enrolled 120 patients with diabetes cataract from May 2019 to May 2021. The patients were divided into two groups: the control group underwent traditional phacoemulsification and Toric IOL implantation, while the treatment group received Len Sx femtosecond laser-assisted treatment. Outcome measures included naked eye vision, astigmatism, high-level ocular phase difference detection, clinical efficacy, and complication. There were no significant preoperative differences in astigmatism or naked eyesight between the two groups. However, postoperative improvements were observed in both groups, with the treatment group showing greater enhancements in naked eye vision and astigmatism six months after the procedure. High-level corneal phase difference tests also indicated significant differences in favor of the treatment group. This study suggests that femtosecond laser-assisted phacoemulsification combined with Toric IOL implantation appears to be more effective in enhancing postoperative vision in diabetic cataract patients compared to traditional methods offering valuable insights for clinical practice.

Microcirculatory alterations and renal outcome following Heart Mate II and 3 Left Ventricular Assist Device implantations

Microcirculatory alterations and renal outcome following Heart Mate II and 3 Left Ventricular Assist Device implantations

Orofacial Manifestation of Systemic Sclerosis: A Cross-Sectional Study and Future Prospects of Oral Capillaroscopy.

oral alterations in Systemic Sclerosis (SSc) patients are widespread and include microstomia, periodontitis, telangiectasias, mandibular resorption, bone lesions, and xerostomia. This cross-sectional study aims to evaluate the differences between SSc patients (cases) and healthy subjects (controls) regarding oral manifestations, quality of life (QoL), and microcirculation alterations. plaque index (PCR), periodontal index (PSR), DMFT, salivary flow rate, and buccal opening were measured by expert clinicians. S-HAQ test, the Self-Rating Anxiety State (SAS), the Self-Rating Depression Scale (SDS), and the WHOQOL-BREF test were administered to patients to evaluate their QoL. Microvascular alterations were assessed by oral videocapillaroscopy, performed on gingival and labial mucosa. A statistical analysis was conducted to find significant differences between healthy people and SSc patients. 59 patients were enrolled in this study. Standard salivary flow is significantly more frequent in controls, while xerostomia, reduced flow, microstomia, lip retraction, and periodontitis are significantly more frequent in the cases. Gingival capillaroscopy showed differences concerning loop visibility, thickening of the gum, tortuosity of gingival loops, and reduced gingival density. Labial capillaroscopy demonstrates that visibility of the labial loops, the labial ectasias, and the tortuosity of the loops are significantly associated with the presence of scleroderma. Hand and facial deformities, hypomobility of the tongue, cheeks, lips, microstomia, and xerostomia significantly compromised the quality of life of SSc patients, which was significantly worse among them. Moreover, oral videocapillaroscopy could be a proper diagnostic method to detect oral microcirculation alterations. SSc patients often present ectasias, rarefaction of the reticulum, microhemorrhages, and megacapillaries, which negatively impact their oral health. periodontitis, reduced salivary flow, and microstomia could be considered SSc oral manifestations. Joint deformities, facial appearance, and comorbidities significantly reduce the QoL of SSc patients compared to healthy subjects. Oral videocapillaroscopy could be an innovative and reliable technique to detect oral microcirculation anomalies.

Angiosome-Targeted Infrapopliteal Angioplasty: Impact on Clinical Outcomes—An Observational Study

Background: Revascularization based on the angiosome concept (AC) is a controversial subject because there is currently no clear evidence of its efficacy, due to the heterogeneity of patients (multiple and diverse risk factors and comorbidities, multiple variations in the affected angiosomes). Choke vessels change the paradigm of the AC, and the presence or absence of the plantar arch directly affects the course of targeted revascularization. The aim of this study was to evaluate the effect of revascularization based on the AC in diabetic patients with chronic limb-threatening ischemia (CLTI). Methods: This retrospective analysis included 51 patients (40 men, 11 women), with a mean age of 69 years (66–72) and a total of 51 limbs, who presented with Rutherford 5–6 CLTI, before and after having undergone a drug-coated balloon angioplasty (8 patients) or plain balloon angioplasty (43). Between November 2018 and November 2019, all patients underwent below-the-knee balloon angioplasties and were followed up for an average of 12 months. The alteration of microcirculation was compared between directly and indirectly revascularized angiosomes. The study assessed clinical findings and patient outcomes, with follow-up investigations, comparing wound healing rates between the different revascularization methods. Patient records and periprocedural leg digital subtraction angiographies (DSA) were analyzed. Differences in outcomes after direct revascularization and indirect percutaneous transluminal angioplasty (PTa) were examined using Cox proportional hazards analysis, with the following endpoints: ulcer healing, limb salvage, and also amputation-free survival. Results: Direct blood flow to the angiosome supplying the ulcer area was achieved in 38 legs, in contrast to 13 legs with indirect revascularization. Among the cases, there were 39 lesions in the anterior tibial artery (ATA), 42 lesions in the posterior tibial artery (PTA), and 8 lesions in the peroneal artery (PA). According to a Cox proportional hazards analysis, having fewer than three (&lt;3) affected angiosomes (HR 0.49, 95% CI 0.19–1.25, p = 0.136) was associated with improved wound healing. Conversely, wound healing outcomes were least favorable after indirect angioplasty (p = 0.206). When adjusting the Cox proportional hazard analysis for the number of affected angiosomes, it was found that direct drug-coated angioplasty resulted in the most favorable wound healing (p = 0.091). At the 1-year follow-up, the major amputation rate was 17.7%, and, according to a Cox proportional hazards analysis, atrial fibrillation (HR 0.85, 95% CI 0.42–1.69, p = 0.637), hemodialysis (HR 1.26, 95% CI 0.39–4.04, p = 0.699), and number of affected angiosomes &gt; 3 (HR 0.94, 95% CI 0.63–1.39, p = 0.748) were significantly associated with poor leg salvage. Additionally, direct endovascular revascularization was associated with a lower rate of major amputation compared to indirect angioplasty (HR 1.09, 95% CI 0.34–3.50, p = 0.884). Conclusions: Observing the angiosomes concept in decision-making appears to result in improved rates of arterial ulcer healing and leg salvage, particularly in targeted drug-coated balloon angioplasty for diabetic critical limb ischemia, where multiple angiosomes are typically affected.

Nail Capillaroscopic Findings in Patients with Heart Failure

Background and Purpose: The nail (fold) microvasculature can be examined non-invasively with capillaroscopy. The endothelium plays a crucial role in atherosclerosis pathogenesis and, in certain instances, the occurance of heart failure. This study was designed to explore microcirculatory alterations by employing nailfold capillaroscopy in individuals with heart failure.&#x0D; &#x0D; Methods: In this observational, prospective study involving individuals with heart failure and controls, nailfold capillaroscopic findings visualized by dermoscopy were evaluated comparatively between the two groups (SPSS version 28.0).&#x0D; &#x0D; Results: A total of 54 participants, consisting of 24 individuals with heart failure and 30 controls without heart failure were included. Nailfold capillaroscopic characteristics significantly more prevalent in the heart failure group compared to the controls included microhemorrhage (70.8% vs. 36.7%), the irregular distribution (20.4% vs. 11.1%), dilation (45.8% vs. 20%) and tortuosity (58.3% vs. 3.3%) (all p0.05).&#x0D; &#x0D; Conclusion: Nailfold capillaroscopy may serve as a useful and easy method to examine systemic microvascular changes in heart failure patients.

Assessment of microcirculatory alteration by a vascular occlusion test using near-infrared spectroscopy in pediatric cardiac surgery: effect of cardiopulmonary bypass

ABSTRACT Objectives Cardiopulmonary bypass cause microcirculatory alterations. Near infrared spectroscopic measurement of tissue oxygen saturation and vascular occlusion test are novel technologies for assessing the microcirculatory function of peripheral tissue specifically in patients undergoing cardiac surgery with cardiopulmonary bypass.Our study aimed to evaluate dynamic microcirculatory function using the vascular occlusion testing during cardiac surgery in pediatric patients. Methods 120 pediatric patients were scheduled. Children had continuous regional oxygen saturation monitoring using near infrared spectroscopy and vascular occlusion test. Vascular occlusion test was performed five times; before induction (T1), after induction (T2), then during cardiopulmonary bypass with full flow (T3), after the termination of CPB (T4) and after sternum closure (T5). Results Basal value was the lowest at T3 and this value was significantly different among measurements (p < 0,01).Values for maximum and minimum tissue oxygen saturation were the lowest at T3 (83,4 and 52,9%).The occlusion slope varied significantly among measurements (p < 0,01).Reperfusion slopes were significantly different among measurements (p < 0,01) with a further progressive decrease in reperfusion slope with duration of cardiopulmonary bypass. Conclusion Microcirculatory function can assessed using VOT with forearm Near-infrared spectroscopy derived variables during cardiopulmonary bypass in pediatric cardiac surgery. Noninvasive assessment of microcirculatory perfusion during cardiopulmonary bypass can further help evaluate and improve circulatory support techniques. Trial Registration The research Project was registered at ClinicalTrials.gov (NCT06191913)

Effect of Respiratory Failure on Peripheral and Organ Perfusion Markers in Severe COVID-19: A Prospective Cohort Study.

Microvascular dysfunction and inflammation caused by COVID-19 disrupt organ function. The study aimed to investigate the association between the severity of SARS-CoV-2 pneumonia and peripheral and organ perfusion as a consequence of altered microcirculation. A total of 116 patients hospitalized due to severe COVID-19 were enrolled in the study. On admission, the patients underwent a Capillary Refill Time (CRT) examination, finger oxygen saturation measurement, thermal imaging of the hand (FIT), and a kidney Doppler ultrasound. Medical data were collected from the medical history. From the evaluated perfusion parameters, only renal cortex perfusion (RCP) was substantially correlated with the CT score (p < 0.010). The peripheral perfusion parameters of Sat., FIT, CRT, and RCP correlated with the ARDS stages (p = 0.0021; p = 0.038; p < 0.0006; p < 0.0002, respectively). The Oxygenation Ratio value (p < 0.001) was significantly associated with all the perfusion parameters (saturation, CRT, FIT, and RCP) in the multivariable regression analysis model. According to the stepwise retrograde regression analysis, RCP was an independent parameter linked with the Oxygenation Ratio (p < 0.001). Severe COVID-19 can result in microvascular dysfunction influencing peripheral and organ perfusion, which can be measured with various methods. The staging of COVID-19 assessed by CT and the Oxygenation Ratio correlates with RCP, CRT, FIT, and oxygen saturation.

The value of contrast-enhanced ultrasound in the diagnosis of microcirculatory perfusion abnormalities in diabetic foot

BackgroundDiabetic foot is one of the most serious complications of type 2 diabetes mellitus (T2DM), and its incidence is increasing in China. Early detection of abnormal microcirculation in the foot is very important for the prevention and treatment of diabetic foot.ObjectiveTo investigate the value of contrast-enhanced ultrasound (CEUS) in diagnosing microcirculatory alterations in the dorsum of the foot for patients with type 2 diabetes mellitus (T2DM).MethodsEighty-eight T2DM patients were included, among them 30 patients sustained diabetes mellitus without complications (group A), 28 with lesions in the dorsum of the foot (no acute infection) that can be classified as Wagner grade 0 ~ 1 (group B), and 30 with lesions in the dorsum of the foot that can be classified as Wagner grade 2–5 (group C). Another 30 healthy adults were included as the control group. All subjects underwent CEUS to examine the dorsalis pedis arteries and blood perfusion to the underlying soft tissues. Parameters of the time-intensity curve (TIC), including rise time (RT), ascending slope (AS), time to peak (TTP), peak intensity (PI), area under the curve (AUC), and half of drop time (DT/2) were analyzed.ResultsThe analysis of TIC data of the dorsalis pedis arteries showed that group C had decreased AS, PI, and AUC and increased TTP, RT, and DT/2 compared with groups A, B, and the control group; the differences were statistically significant (p < 0.05). The analysis of TIC data of the perfusion to the underlying soft tissues showed that AS, PI, and AUC decreased from the control group through group A, B, and then C; the differences were all statistically significant (p < 0.05). The TIC data were correlated with the severity of microcirculatory impairment in the dorsum of the foot and among them the AUC, PI, and AS had higher predictive value.ConclusionsMicrocirculatory impairment in the dorsum of the foot in T2DM patients presents itself as “delayed wash-in, delayed wash-out, and weak enhancement” on CEUS images. CEUS can provide quantification of the microcirculatory changes in the soft tissues in the dorsum of the foot and reflect the differences of microcirculatory perfusion across different grades of lesions.