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INTRODUCTION: Sufficient perfusion is essential for a safe intestinal anastomosis. Impaired microcirculation may lead to increased bacterial translocation and anastomosis insufficiency. Thus, it is important to estimate well the optimal distance of the anastomosis line from the last mesenterial vessel. However, it is still empiric. In this experiment the aim was to investigate the intestinal microcirculation at various distances from the anastomosis in a pig model. MATERIALS AND METHODS: On 8 anesthetized pigs paramedian laparotomy and end-to-end jejuno-jejunostomy were performed. Using Cytocam-IDF camera, microcirculatory recordings were taken before surgery at the planned suture line, and 1 to 3 mesenterial vessel mural trunk distance from it, and at the same sites 15 and 120 min after anastomosis completion. After the microcirculation monitoring, anastomosed and intact bowel segments were removed to test tensile strength. RESULTS: The proportion and the density of the perfused vessels decreased significantly after anastomosis completion. The perfusion rate increased gradually distal from the anastomosis, and after 120 min these values seemed to be normalized. Anastomosed bowels had significantly lower maximal tensile strength and higher slope of tensile strength curves than intact controls. CONCLUSION: Alterations in microcirculation and tensile strength were observed. After completing the anastomosis, the improvement in perfusion increased gradually away from the wound edge. The IDF device was useful to monitor intestinal microcirculation providing data to estimate better the optimal distance of the anastomosis from the last order mesenteric vessel.

Asunto(s)

Anastomosis Quirúrgica , Microcirculación , Modelos Animales , Sus scrofa , Resistencia a la Tracción , Animales , Factores de Tiempo , Yeyunostomía , Flujo Sanguíneo Regional , Yeyuno/irrigación sanguínea , Yeyuno/cirugía , Velocidad del Flujo Sanguíneo , Intestino Delgado/irrigación sanguínea , Intestino Delgado/cirugía , Femenino

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BACKGROUND: Ninety percent of cervical cancer (CC) diagnoses and deaths occur in low and middle-income countries (LMICs). Especially in these countries, where human and material resources are limited, there is a need for real-time screening methods that enable immediate treatment decisions (i.e., 'see and treat'). OBJECTIVE: To evaluate whether handheld vital microscopy (HVM) enables real-time detection of microvascular alterations associated with cervical intraepithelial neoplasia (CIN) and CC. METHODS: A cross-sectional study was conducted in an oncologic hospital and outpatient clinic, and included ten healthy controls, ten women with CIN, and ten women with CC. The microvasculature was assessed in four quadrants of the uterine cervix using HVM. The primary outcome was the presence of abnormal angioarchitecture (AA). Secondary outcomes included capillary loop density (CD), total vessel density (TVD), functional capillary density (FCD), and the proportion of perfused vessels (PPV). RESULTS: 198 image sequences of the cervical microvasculature were recorded. Compared to healthy controls, significantly more abnormal image sequences were observed in women with high-grade CIN (11 % vs. 44 %, P < 0.001) and women with CC (11 % vs. 69 %, P < 0.001). TVD, FCD, and PPV were lower in women with CIN and CC. CONCLUSIONS: HVM enables easy, real-time, non-invasive assessment of cervical lesions through the detection of microvascular alterations. Thereby, HVM potentially provides an opportunity for point-of-care screening, which may enable immediate treatment decisions (see and treat) and reduce the number of unnecessary surgical interventions.

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Displasia del Cuello del Útero , Neoplasias del Cuello Uterino , Femenino , Humanos , Neoplasias del Cuello Uterino/diagnóstico , Neoplasias del Cuello Uterino/patología , Microscopía , Estudios Transversales , Microcirculación , Displasia del Cuello del Útero/diagnóstico , Displasia del Cuello del Útero/patología , Displasia del Cuello del Útero/cirugía

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OBJECTIVES: The objective of the study was to better understand the extent of the ischemic trauma and the effects of surgical repair on the vaginal microcirculation in patients with obstetric vesicovaginal fistula (VVF). DESIGN: In this observational study, we evaluated the vaginal microvasculature surrounding VVF using handheld vital microscopy (HVM) before, during, and 2 weeks after surgical VVF repair. PARTICIPANTS: Seventeen women undergoing VVF repair were included in this study. SETTING: The study was conducted in the Fistula Care Centre in Lilongwe, Malawi. METHODS: We used HVM with incident dark-field imaging to non-invasively visualize the microvasculature of the vaginal tissue surrounding fistulas. The primary outcome was the presence of microvascular flow. Secondary outcomes included angioarchitecture, fistula closure (postoperative dye test), and urinary continence (pad weight test). RESULTS: Microvascular flow was present before, during, and after surgical repair in, respectively, 83.8%, 83.9%, and 93.4% of obtained image sequences. The angioarchitecture was normal in 75.8% of the image sequences before surgery, 69.4% at fistula closure, and 89.1% two weeks after VVF repair. Fourteen (82.4%) patients had a closed fistula after surgical repair. LIMITATIONS: The study was limited by the lack of a control group and the relatively small sample size. CONCLUSION: Although the vaginal microcirculation in women with VVF is compromised, extensive ischemic damage is not observed in the tissue surrounding fistulas. This suggests significant regenerative capacity of the vaginal vasculature in young women, or less extensive ischemic damage than presumed. Following surgical repair, we observed improvement of microcirculatory flow and angioarchitecture, suggesting that surgery is a good option for patients with obstetric VVF.

Asunto(s)

Fístula Vesicovaginal , Embarazo , Humanos , Femenino , Fístula Vesicovaginal/cirugía , Microcirculación , Vagina/cirugía , Estudios Retrospectivos

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BACKGROUND: Late side effects of radiotherapy in patients with head and neck cancer (HNCPs) result in decreased tissue vascularity, a compromised healing capacity and spontaneous breakdown of tissue. The aim of this study was to examine the in vivo effect of hyperbaric oxygen therapy (HBOT) on the microcirculation in irradiated oral tissue. METHODS: Using a handheld microscope, the effect of HBOT on oral mucosal microcirculation parameters was measured in 34 previously irradiated HNCPs prior to HBOT and at 4 weeks and 6 months posttreatment. RESULTS: A significant increase in mean buccal vessel density and decrease in buccal vessel diameter was found 6 months after HBOT compared to baseline, 22 ± 11 versus 25 ± 7 cpll/mm2 (p < 0.05) and 20 ± 4 versus 16 ± 5 µm (p < 0.05), respectively. CONCLUSION: Our results indicate that oral microcirculation histopathology associated with irradiation is able to respond to HBOT by redirecting oral microcirculation parameters towards values consistent with healthy tissue.

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Neoplasias de Cabeza y Cuello , Oxigenoterapia Hiperbárica , Traumatismos por Radiación , Progresión de la Enfermedad , Neoplasias de Cabeza y Cuello/etiología , Neoplasias de Cabeza y Cuello/radioterapia , Humanos , Oxigenoterapia Hiperbárica/métodos , Microcirculación/efectos de la radiación , Mucosa Bucal , Traumatismos por Radiación/etiología , Traumatismos por Radiación/terapia

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Background: Blood cardioplegia attenuates cardiopulmonary bypass (CPB)-induced systemic inflammatory response in patients undergoing cardiac surgery, which may favorably influence the microvascular system in this cohort. The aim of this study was to investigate whether blood cardioplegia would offer advantages over crystalloid cardioplegia in the preservation of microcirculation in patients undergoing coronary artery bypass grafting (CABG) with CPB. Methods: In this prospective observational cohort study, 20 patients who received crystalloid (n = 10) or blood cardioplegia (n = 10) were analyzed. The microcirculatory measurements were obtained sublingually using incident dark-field imaging at five time points ranging from the induction of anesthesia (T0) to discontinuation of CPB (T5). Results: In the both crystalloid [crystalloid cardioplegia group (CCG)] and blood cardioplegia [blood cardioplegia group (BCG)] groups, perfused vessel density (PVD), total vessel density (TVD), and proportion of perfused vessels (PPV) were reduced after the beginning of CPB. The observed reduction in microcirculatory parameters during CPB was only restored in patients who received blood cardioplegia and increased to baseline levels as demonstrated by the percentage changes from T0 to T5 (%Δ)T0-T5 in all the functional microcirculatory parameters [%ΔTVDT0-T5(CCG): -10.86 ± 2.323 vs. %ΔTVDT0-T5(BCG): 0.0804 ± 1.107, p < 0.001; %ΔPVDT0-T5(CCG): -12.91 ± 2.884 vs. %ΔPVDT0-T5(BCG): 1.528 ± 1.144, p < 0.001; %ΔPPVT0-T5(CCG): -2.345 ± 1.049 vs. %ΔPPVT0-T5(BCG): 1.482 ± 0.576, p < 0.01]. Conclusion: Blood cardioplegia ameliorates CPB-induced microcirculatory alterations better than crystalloid cardioplegia in patients undergoing CABG, which may reflect attenuation of the systemic inflammatory response. Future investigations are needed to identify the underlying mechanisms of the beneficial effects of blood cardioplegia on microcirculation.

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Most women with epithelial ovarian cancer (EOC) suffer from peritoneal carcinomatosis upon first clinical presentation. Extensive peritoneal carcinomatosis has a poor prognosis and its pathophysiology is not well understood. Although treatment with systemic intravenous chemotherapy is often initially successful, peritoneal recurrences occur regularly. We hypothesized that insufficient or poorly-perfused microvasculature may impair the therapeutic efficacy of systemic intravenous chemotherapy but may also limit expansive and invasive growth characteristic of peritoneal EOC metastases. In 23 patients with advanced EOC or suspicion thereof, we determined the angioarchitecture and perfusion of the microvasculature in peritoneum and in peritoneal metastases using incident dark field (IDF) imaging. Additionally, we performed immunohistochemical analysis and 3-dimensional (3D) whole tumor imaging using light sheet fluorescence microscopy of IDF-imaged tissue sites. In all metastases, microvasculature was present but the angioarchitecture was chaotic and the vessel density and perfusion of vessels was significantly lower than in unaffected peritoneum. Immunohistochemical analysis showed expression of vascular endothelial growth factor and hypoxia inducible factor 1α, and 3D imaging demonstrated vascular continuity between metastases and the vascular network of the peritoneum beneath the elastic lamina of the peritoneum. We conclude that perfusion of the microvasculature within metastases is limited, which may cause hypoxia, affect the behavior of EOC metastases on the peritoneum and limit the response of EOC metastases to systemic treatment.

Asunto(s)

Carcinoma Epitelial de Ovario/irrigación sanguínea , Microvasos/diagnóstico por imagen , Neoplasias Ováricas/terapia , Neoplasias Peritoneales/irrigación sanguínea , Peritoneo/patología , Anciano , Anciano de 80 o más Años , Antineoplásicos/uso terapéutico , Carcinoma Epitelial de Ovario/secundario , Carcinoma Epitelial de Ovario/terapia , Hipoxia de la Célula , Quimioterapia Adyuvante , Procedimientos Quirúrgicos de Citorreducción , Femenino , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/análisis , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Imagenología Tridimensional , Inmunohistoquímica , Microvasos/patología , Persona de Mediana Edad , Terapia Neoadyuvante , Neoplasias Ováricas/patología , Ovariectomía , Ovario/patología , Ovario/cirugía , Neoplasias Peritoneales/prevención & control , Neoplasias Peritoneales/secundario , Peritoneo/irrigación sanguínea , Estudios Prospectivos , Resultado del Tratamiento , Factor A de Crecimiento Endotelial Vascular/análisis , Factor A de Crecimiento Endotelial Vascular/metabolismo

RESUMEN

OBJECTIVE: The aim of this study was to apply an innovative methodology to incident dark-field (IDF) imaging in coronary artery bypass grafting (CABG) patients for the identification and quantification of rolling leukocytes along the sublingual microcirculatory endothelium. METHODS: This study was a post hoc analysis of a prospective study that evaluated the perioperative course of the sublingual microcirculation in CABG patients. Video images were captured using IDF imaging following the induction of anesthesia (T0) and cardiopulmonary bypass (CPB) (T1) in 10 patients. Rolling leukocytes were identified and quantified using frame averaging, which is a technique that was developed for correctly identifying leukocytes. RESULTS: The number of rolling leukocytes increased significantly from T0 (7.5 [6.4-9.1] leukocytes/capillary-postcapillary venule/4 s) to T1 (14.8 [13.2-15.5] leukocytes/capillary-postcapillary venule/4 s) (p < 0.0001). A significant increase in systemic leukocyte count was also detected from 7.4 ± 0.9 × 109/L (preoperative) to 12.4 ± 4.4 × 109/L (postoperative) (p < 0.01). CONCLUSION: The ability to directly visualize leukocyte-endothelium interaction using IDF imaging facilitates the diagnosis of a systemic inflammatory response after CPB via the identification of rolling leukocytes. Integration of the frame averaging algorithm into the software of handheld vital microscopes may enable the use of microcirculatory leukocyte count as a real-time parameter at the bedside.

Asunto(s)

Puente de Arteria Coronaria , Endotelio/fisiología , Leucocitos/fisiología , Suelo de la Boca/irrigación sanguínea , Anciano , Puente Cardiopulmonar , Femenino , Humanos , Masculino , Microcirculación , Persona de Mediana Edad , Estudios Prospectivos

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Severe malaria is mostly caused by Plasmodium falciparum, resulting in considerable, systemic inflammation and pronounced endothelial activation. The endothelium forms an interface between blood and tissue, and vasculopathy has previously been linked with malaria severity. We studied the extent to which the endothelial glycocalyx that normally maintains endothelial function is involved in falciparum malaria pathogenesis by using incident dark-field imaging in the buccal mucosa. This enabled calculation of the perfused boundary region, which indicates to what extent erythrocytes can permeate the endothelial glycocalyx. The perfused boundary region was significantly increased in severe malaria patients and mirrored by an increase of soluble glycocalyx components in plasma. This is suggestive of a substantial endothelial glycocalyx loss. Patients with severe malaria had significantly higher plasma levels of sulfated glycosaminoglycans than patients with uncomplicated malaria, whereas other measured glycocalyx markers were raised to a comparable extent in both groups. In severe malaria, the plasma level of the glycosaminoglycan hyaluronic acid was positively correlated with the perfused boundary region in the buccal cavity. Plasma hyaluronic acid and heparan sulfate were particularly high in severe malaria patients with a low Blantyre coma score, suggesting involvement in its pathogenesis. In vivo imaging also detected perivascular hemorrhages and sequestering late-stage parasites. In line with this, plasma angiopoietin-1 was decreased while angiopoietin-2 was increased, suggesting vascular instability. The density of hemorrhages correlated negatively with plasma levels of angiopoietin-1. Our findings indicate that as with experimental malaria, the loss of endothelial glycocalyx is associated with vascular dysfunction in human malaria and is related to severity.

Asunto(s)

Endotelio Vascular/patología , Glicocálix/patología , Malaria Falciparum/patología , Mucosa Bucal/patología , Hemorragia Bucal/patología , Angiopoyetina 1/sangre , Angiopoyetina 2/sangre , Biomarcadores/sangre , Niño , Preescolar , Endotelio Vascular/fisiopatología , Femenino , Glicosaminoglicanos/sangre , Humanos , Lactante , Malaria Falciparum/sangre , Malaria Falciparum/diagnóstico por imagen , Malaria Falciparum/fisiopatología , Masculino , Mucosa Bucal/irrigación sanguínea , Mucosa Bucal/diagnóstico por imagen , Mucosa Bucal/fisiopatología , Hemorragia Bucal/sangre , Hemorragia Bucal/diagnóstico por imagen , Hemorragia Bucal/fisiopatología

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This paper briefly reviews the physiological components of the microcirculation, focusing on its function in homeostasis and its central function in the realization of oxygen transport to tissue cells. Its pivotal role in the understanding of circulatory compromise in states of shock and renal compromise is discussed. Our introduction of hand-held vital microscopes (HVM) to clinical medicine has revealed the importance of the microcirculation as a central target organ in states of critical illness and inadequate response to therapy. Technical and methodological developments have been made in hardware and in software including our recent introduction and validation of automatic analysis software called MicroTools, which now allows point-of-care use of HVM imaging at the bedside for instant availability of functional microcirculatory parameters needed for microcirculatory targeted resuscitation procedures to be a reality.

Asunto(s)

Procesamiento de Imagen Asistido por Computador , Microscopía Intravital , Enfermedades Renales , Microcirculación , Sistemas de Atención de Punto , Choque , Programas Informáticos , Humanos , Enfermedades Renales/diagnóstico por imagen , Enfermedades Renales/fisiopatología , Choque/diagnóstico por imagen , Choque/fisiopatología

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BACKGROUND AND AIM: Liver cirrhosis is associated with widespread microcirculatory dysfunction and hemodynamic derangement, which may play a role in the pathogenesis of multiple organ failure. Little is known, however, about the progression of microvascular alterations as the severity of liver disease worsens. Therefore, our aim is to quantify the peripheral systemic microcirculatory changes associated with increasing severity of liver cirrhosis. METHODS: Forty patients with liver cirrhosis were studied and divided into groups based on Child-Pugh classes A (n = 9), B (n = 18), and C (n = 13) for comparison. Incident dark field imaging was used to evaluate the sublingual microcirculation and near-infrared spectroscopy at the thenar eminence to assess microvascular reactivity and function. RESULTS: There was no difference in microcirculatory flow index (P = 0.655), heterogeneity index (P = 0.702), or vessel density (P = 0.923) between the different Child-Pugh groups. Microvascular reactivity did not change as the severity of liver disease worsened. CONCLUSIONS: This study showed no association between peripheral systemic microcirculatory alterations and the severity of liver disease. Further research with larger study cohorts are needed to clarify the relationship between microcirculatory abnormalities and disease progression and to establish if the peripheral microcirculation is affected by the pathophysiology of worsening cirrhosis.

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INTRODUCTION: Intestinal blood flow is often named as a key factor in the pathophysiology of anastomotic leakage. The distribution between mucosal and serosal microperfusion during surgery remains to be elucidated. OBJECTIVE: The aim of this study was to assess if the mucosal microcirculation of the intestine is more vulnerable to a surgical hit than the serosal microcirculation during surgery. METHODS: In an observational cohort study (n = 9 patients), the microcirculation of the bowel serosa and mucosa was visualized with incident dark-field imaging during surgery. At the planned anastomosis, the following microcirculatory parameters were determined: microvascular flow index (MFI), percentage of perfused vessels (PPV), perfused vessel density (PVD), and total vessel density (TVD). Data are presented as median (interquartile range [IQR]). RESULTS: Perfusion parameters and vessel density were significantly higher for the mucosa than the serosal microcirculation at the planned site for anastomosis or stoma. Mucosal MFI was 3.00 (IQR 3.00-3.00) compared to a serosal MFI of 2.75 (IQR 2.21-2.94), p = 0.03. The PPV was 99% (IQR 98-100) versus 92% (IQR 66-94), p = 0.01. The TVD was 16.77 mm/mm2 (IQR 13.04-18.01) versus 10.42 mm/mm2 (IQR 9.36-11.81), p = 0.01, and the PVD was 15.44 mm/mm2 (IQR 13.04-17.78) versus 9.02 mm/mm2 (IQR 6.43-9.43), p = 0.01. CONCLUSIONS: The mucosal microcirculation was preserved, while lower perfusion of the serosa was found at the planned anastomosis or stoma during surgery. Further research is needed to link our observations to the clinically relevant endpoint of anastomotic leakage.

Asunto(s)

Abdomen/cirugía , Anastomosis Quirúrgica/métodos , Mucosa Intestinal/irrigación sanguínea , Microcirculación/fisiología , Membrana Serosa/irrigación sanguínea , Anciano , Femenino , Humanos , Masculino , Microscopía , Persona de Mediana Edad

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The European Society of Intensive Care Medicine (ESICM) issued the second consensus on the assessment of sublingual microcirculation in critically ill patients. This paper interprets the consensus for clinicians about: what is microcirculation, how to observe microcirculation, and the details of microcirculation images collection and parameters analysis. Besides, this paper illustrates the relationship between microcirculation alternation and shock, it also evaluates the present situation and future development of microcirculation monitoring.

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BACKGROUND: Management of tissue perfusion following cardiac surgery is a challenging task where common clinical parameters do not reflect microcirculatory dysfunction. Heterogeneity in blood flow perfusion and abnormalities in capillary density characterize microcirculatory dysfunction. The restoration of a normal microcirculation may become a novel target for therapy in the future in addition to macrocirculatory parameters. The aim of this study is to determine how the sublingual microcirculatory parameters vary at the bedside in post-cardiac surgery patients which underwent diuretic therapy to correct fluid overload. METHODS: In this prospective observational pilot study, video clips of sublingual microcirculation in post-cardiac surgery patients receiving furosemide and/or spironolactone to achieve normal fluid balance were recorded using Cytocam-IDF imaging. Data was obtained on the first (T0), second (T1), and third (T2) day after the patients left the intensive care unit (ICU). Measurements were analyzed off-line to obtain the following microcirculatory parameters: total vessel density (TVD), microcirculatory flow index (MFI), proportion of perfused vessel (PPV), and perfused vessel density (PVD). Macrocirculatory parameters and body weight were also collected at these time points. RESULTS: Ninety measurements were performed in ten post ICU cardiac surgery patients. Thirteen measurements were excluded due to quality reasons; these excluded measurements were spread across the patients and time points, and there was no loss of patients or time points. An increase in TVD was observed from T0 to T1 (20 ± 2.7 to 24 ± 3.2 mm/mm2; p = 0.0410) and from T0 to T2 (20 ± 2.7 to 26 ± 3.3 mm/mm2; p = 0.0005). An increase in PVD was present from T0 to T1 (19 ± 2.3 to 24 ± 3.5 mm/mm2; p = 0.0072) and from T0 to T2 (19 ± 2.3 to 26 ± 3.4 mm/mm2, p = 0.0008). Fluid overload was assessed through a positive cumulative fluid balance on the day of ICU discharge. CONCLUSIONS: Cytocam-IDF imaging to monitor microcirculation as a daily parameter is feasible and could become a valuable tool to non-invasively assess the tissue oxygenation at the bedside. An increase in TVD and PVD (functional capillary density) indicated the recruitment of the sublingual microcirculation in patients with diuretic therapy. Future research is needed to prove the correlation between the recruitment of the sublingual microcirculation and the de-escalation phase of the fluid management.

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BACKGROUND/AIMS: This study describes the peritoneal microcirculation, compares quantitative parameters and angioarchitecture to the standard of sublingual microcirculatory assessment, and determines the practical feasibility of this method. METHODS: Incident dark field imaging was performed of the peritoneum and sublingually to determine angioarchitecture, total and perfused vessel density (TVD and PVD), the proportion of perfused vessels (PPV), the microvascular flow index (MFI) and image acquisition time. RESULTS: Peritoneal angioarchitecture was characterized by a quadrangular network of longitudinally oriented capillaries, often flanked by fat cells. Differences between peritoneal and sublingual microcirculation were observed with regard to TVD (peritoneum 12 mm/mm2 [95% CI 10-14] vs. sublingual 23 mm/mm2 [95% CI 21-25]; p < 0.0001), PVD (peritoneum 11 mm/mm2 [95% CI 9-13] vs. sublingual 23 mm/mm2 [95% CI 21-25]; p < 0.0001), PPV (peritoneum 88% [95% CI 79-97] vs. sublingual 99% [95% CI 99-100]; p = 0.014), and MFI (peritoneum 3 [IQR 2.3-3.0] vs. sublingual 3 [IQR 3.0-3.0]; p = 0.012). There was no difference in image acquisition time (peritoneum 2: 34 min [95% CI 1: 49-3: 19] vs. sublingual 2: 38 [95% CI 1: 37-3: 32]; p = 0.916). CONCLUSION: The peritoneal microcirculation was characterized by a low capillary density and a distinctive angioarchitecture. The possibility of peri-toneal microcirculatory assessment offers promise for the study of peritoneal (patho-)physiology and (monitoring or detection of) associated diseases.

Asunto(s)

Capilares/fisiología , Microcirculación , Peritoneo/irrigación sanguínea , Lengua/irrigación sanguínea , Adulto , Anciano , Velocidad del Flujo Sanguíneo , Estudios de Factibilidad , Femenino , Hepatectomía , Humanos , Interpretación de Imagen Asistida por Computador , Periodo Intraoperatorio , Masculino , Microscopía por Video , Persona de Mediana Edad , Flujo Sanguíneo Regional , Factores de Tiempo

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As of now the relationship between glycocalyx degradation and microcirculatory perfusion abnormalities in non-septic critical ill patients is unclear. In addition, conjunctival sidestream dark field-imaging for the purpose of glycocalyx thickness estimation has never been performed. We aimed to investigate whether changes in glycocalyx thickness in non-septic patients are associated with microcirculatory alterations in conjunctival and sublingual mucosa. In this single-centre prospective observational study, using techniques for direct in-vivo observation of the microcirculation, we performed a single measurement of microcirculatory perfusion parameters and visualized glycocalyx thickness in both ocular conjunctiva and sublingual mucosa in mixed cardio surgical (n = 18) and neurocritical patients (n = 27) and compared these data with age-matched healthy controls (n = 20). In addition we measured systemic syndecan-1 levels. In the sublingual and conjunctival region we observed a significant increase of the perfused boundary region (PBR) in both neuro-critical and cardiac surgical ICU patients, compared to controls. There was a significant increase of syndecan-1 in ICU patients comparing with controls and in cardiac patients comparing with neurological (120.0[71.0-189.6] vs. 18.0[7.2-40.7], p < 0.05). We detected a weak correlation between syndecan-1 and sublingual PBR but no correlations between global glycocalyx damage and conjuctival glycocalyx thickness. We found significantly lower perfused vessel density (PVD) of small vessels in sublingual mucosa in patients after cardiac surgery in comparison with healthy subjects. In neuro-critical, but not cardiac surgery patients conjunctival TVD and PVD of small vessels were found to be significantly lower in comparison with controls.

Asunto(s)

Procedimientos Quirúrgicos Cardíacos , Conjuntiva/irrigación sanguínea , Glicocálix/patología , Microcirculación , Microvasos/fisiopatología , Mucosa Bucal/irrigación sanguínea , Enfermedades del Sistema Nervioso/patología , Enfermedades del Sistema Nervioso/fisiopatología , Anciano , Biomarcadores/sangre , Procedimientos Quirúrgicos Cardíacos/efectos adversos , Estudios de Casos y Controles , Enfermedad Crítica , Femenino , Glicocálix/metabolismo , Humanos , Masculino , Microvasos/patología , Persona de Mediana Edad , Enfermedades del Sistema Nervioso/sangre , Estudios Prospectivos , Flujo Sanguíneo Regional , Sindecano-1/sangre

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Cardiac arrest represents a leading cause of mortality and morbidity in developed countries. Extracorporeal cardiopulmonary resuscitation (ECPR) increases the chances for a beneficial outcome in victims of refractory cardiac arrest. However, ECPR and post-cardiac arrest care are affected by high mortality rates due to multi-organ failure syndrome, which is closely related to microcirculatory disorders. Therefore, microcirculation represents a key target for therapeutic interventions in post-cardiac arrest patients. However, the evaluation of tissue microcirculatory perfusion is still demanding to perform. Novel videomicroscopic technologies (Orthogonal polarization spectral, Sidestream dark field and Incident dark field imaging) might offer a promising way to perform bedside microcirculatory assessment and therapy monitoring. This review aims to summarise the recent body of knowledge on videomicroscopic imaging in a cardiac arrest setting and to discuss the impact of extracorporeal reperfusion and other therapeutic modalities on microcirculation.

Asunto(s)

Diagnóstico por Imagen/métodos , Paro Cardíaco/sangre , Microcirculación/fisiología , Humanos , Perfusión

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BACKGROUND: Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is increasingly adopted for the treatment of cardiogenic shock (CS). However, a marker of successful weaning remains largely unknown. Our hypothesis was that successful weaning is associated with sustained microcirculatory function during ECMO flow reduction. Therefore, we sought to test the usefulness of microcirculatory imaging in the same sublingual spot, using incident dark field (IDF) imaging in assessing successful weaning from VA-ECMO and compare IDF imaging with echocardiographic parameters. METHODS: Weaning was performed by decreasing the VA-ECMO flow to 50% (F50) from the baseline. The endpoint of the study was successful VA-ECMO explantation within 48 hours after weaning. The response of sublingual microcirculation to a weaning attempt (WA) was evaluated. Microcirculation was measured in one sublingual area (single spot (ss)) using CytoCam IDF imaging during WA. Total vessel density (TVDss) and perfused vessel density (PVDss) of the sublingual area were evaluated before and during 50% flow reduction (TVDssF50, PVDssF50) after a WA and compared to conventional echocardiographic parameters as indicators of the success or failure of the WA. RESULTS: Patients (n = 13) aged 49 ± 18 years, who received VA-ECMO for the treatment of refractory CS due to pulmonary embolism (n = 5), post cardiotomy (n = 3), acute coronary syndrome (n = 2), myocarditis (n = 2) and drug intoxication (n = 1), were included. TVDssF50 (21.9 vs 12.9 mm/mm2, p = 0.001), PVDssF50 (19.7 vs 12.4 mm/mm2, p = 0.01) and aortic velocity-time integral (VTI) at 50% flow reduction (VTIF50) were higher in patients successfully weaned vs not successfully weaned. The area under the curve (AUC) was 0.99 vs 0.93 vs 0.85 for TVDssF50 (small vessels) >12.2 mm/mm2, left ventricular ejection fraction (LVEF) >15% and aortic VTI >11 cm. Likewise, the AUC was 0.91 vs 0.93 vs 0.85 for the PVDssF50 (all vessels) >14.8 mm/mm2, LVEF >15% and aortic VTI >11 cm. CONCLUSION: This study identified sublingual microcirculation as a novel potential marker for identifying successful weaning from VA-ECMO. Sustained values of TVDssF50 and PVDssF50 were found to be specific and sensitive indicators of successful weaning from VA-ECMO as compared to echocardiographic parameters.

Asunto(s)

Oxigenación por Membrana Extracorpórea/normas , Microcirculación/fisiología , Suelo de la Boca/irrigación sanguínea , Pronóstico , Desconexión del Ventilador/normas , Adulto , Anciano , Anciano de 80 o más Años , Oxigenación por Membrana Extracorpórea/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Suelo de la Boca/fisiopatología , Estudios Prospectivos , Choque Cardiogénico/clasificación , Desconexión del Ventilador/métodos

RESUMEN

INTRODUCTION: The outcome of patients in septic shock has been shown to be related to changes within the microcirculation. Modern imaging technologies are available to generate high resolution video recordings of the microcirculation in humans. However, evaluation of the microcirculation is not yet implemented in the routine clinical monitoring of critically ill patients. This is mainly due to large amount of time and user interaction required by the current video analysis software. The aim of this study was to validate a newly developed automated method (CCTools®) for microcirculatory analysis of sublingual capillary perfusion in septic patients in comparison to standard semi-automated software (AVA3®). METHODS: 204 videos from 47 patients were recorded using incident dark field (IDF) imaging. Total vessel density (TVD), proportion of perfused vessels (PPV), perfused vessel density (PVD), microvascular flow index (MFI) and heterogeneity index (HI) were measured using AVA3® and CCTools®. RESULTS: Significant differences between the numeric results obtained by the two different software packages were observed. The values for TVD, PVD and MFI were statistically related though. CONCLUSION: The automated software technique successes to show septic shock induced microcirculation alterations in near real time. However, we found wide degrees of agreement between AVA3® and CCTools® values due to several technical factors that should be considered in the future studies.

Asunto(s)

Microcirculación/fisiología , Absorción por la Mucosa Oral/fisiología , Choque Séptico/terapia , Adulto , Capilares , Femenino , Humanos , Masculino , Persona de Mediana Edad , Programas Informáticos

RESUMEN

Analysis of the microcirculation is currently performed offline, is time consuming and operator dependent. The aim of this study was to assess the ability and efficiency of the automatic analysis software CytoCamTools 1.7.12 (CC) to measure microvascular parameters in comparison with Automated Vascular Analysis (AVA) software 3.2. 22 patients admitted to the cardiothoracic intensive care unit following cardiac surgery were prospectively enrolled. Sublingual microcirculatory videos were analysed using AVA and CC software. The total vessel density (TVD) for small vessels, perfused vessel density (PVD) and proportion of perfused vessels (PPV) were calculated. Blood flow was assessed using the microvascular flow index (MFI) for AVA software and the averaged perfused speed indicator (APSI) for the CC software. The duration of the analysis was also recorded. Eighty-four videos from 22 patients were analysed. The bias between TVD-CC and TVD-AVA was 2.20 mm/mm2 (95 % CI 1.37-3.03) with limits of agreement (LOA) of -4.39 (95 % CI -5.66 to -3.16) and 8.79 (95 % CI 7.50-10.01) mm/mm2. The percentage error (PE) for TVD was ±32.2 %. TVD was positively correlated between CC and AVA (r = 0.74, p < 0.001). The bias between PVD-CC and PVD-AVA was 6.54 mm/mm2 (95 % CI 5.60-7.48) with LOA of -4.25 (95 % CI -8.48 to -0.02) and 17.34 (95 % CI 13.11-21.57) mm/mm2. The PE for PVD was ±61.2 %. PVD was positively correlated between CC and AVA (r = 0.66, p < 0.001). The median PPV-AVA was significantly higher than the median PPV-CC [97.39 % (95.25, 100 %) vs. 81.65 % (61.97, 88.99), p < 0.0001]. MFI categories cannot estimate or predict APSI values (p = 0.45). The time required for the analysis was shorter with CC than with AVA system [2'42″ (2'12″, 3'31″) vs. 16'12″ (13'38″, 17'57″), p < 0.001]. TVD is comparable between the two softwares, although faster with CC software. The values for PVD and PPV are not interchangeable given the different approach to assess microcirculatory flow.

Asunto(s)

Procesamiento de Imagen Asistido por Computador , Microcirculación , Reconocimiento de Normas Patrones Automatizadas , Programas Informáticos , Automatización , Velocidad del Flujo Sanguíneo , Vasos Sanguíneos/diagnóstico por imagen , Cuidados Críticos , Humanos , Unidades de Cuidados Intensivos , Microscopía por Video , Variaciones Dependientes del Observador , Perfusión , Estudios Prospectivos , Reproducibilidad de los Resultados

RESUMEN

The developing human fetus is able to cope with the physiological reduction in oxygen supply occurring in utero. However, it is not known if microvascularization of the fetus is augmented when pregnancy occurs at high altitude. Fifty-three healthy term newborns in Puno, Peru (3,840 m) were compared with sea-level controls. Pre- and postductal arterial oxygen saturation (SpO2) was determined. Cerebral and calf muscle regional tissue oxygenation was measured using near infrared spectroscopy (NIRS). Skin microcirculation was noninvasively measured using incident dark field imaging. Pre- and postductal SpO2 in Peruvian babies was 88.1 and 88.4%, respectively, which was 10.4 and 9.7% lower than in newborns at sea level (P < 0.001). Cerebral and regional oxygen saturation was significantly lower in the Peruvian newborns (cerebral: 71.0 vs. 74.9%; regional: 68.5 vs. 76.0%, P < 0.001). Transcutaneously measured total vessel density in the Peruvian newborns was 14% higher than that in the newborns born at sea level (29.7 vs. 26.0 mm/mm(2); P ≤ 0.001). This study demonstrates that microvascular vessel density in neonates born to mothers living at high altitude is higher than that in neonates born at sea level.

Asunto(s)

Aclimatación/fisiología , Altitud , Recién Nacido/fisiología , Microcirculación/fisiología , Microvasos/anatomía & histología , Microvasos/fisiología , Embarazo/fisiología , Adulto , Femenino , Humanos , Masculino , Perú , Estudios Prospectivos , Adulto Joven