Noninvasive assessment of human microvascular function in health and disease using incident dark-field microscopy.

Reduced peripheral microvascular reactivity is associated with an increased risk for major adverse cardiac events (MACEs). Tools for noninvasive assessment of peripheral microvascular function are limited, and existing technology is poorly validated in both healthy populations and patients with cardiovascular disease (CVD). Here, we used a handheld incident dark-field imaging tool (CytoCam) to test the hypothesis that, compared with healthy individuals (no risk factors for CVD), subjects formally diagnosed with coronary artery disease (CAD) or those with ≥2 risk factors for CAD (at risk) would exhibit impaired peripheral microvascular reactivity. A total of 17 participants (11 healthy, 6 at risk) were included in this pilot study. CytoCam was used to measure sublingual microvascular total vessel density (TVD), perfused vessel density (PVD), and microvascular flow index (MFI) in response to the topical application of acetylcholine (ACh) and sublingual administration of nitroglycerin (NTG). Baseline MFI and PVD were significantly reduced in the at-risk cohort compared with healthy individuals. Surprisingly, following the application of acetylcholine and nitroglycerin, both groups showed a significant improvement in all three microvascular perfusion parameters. These results suggest that, despite baseline reductions in both microvascular density and perfusion, human in vivo peripheral microvascular reactivity to both endothelial-dependent and -independent vasoactive agents remains intact in individuals with CAD or multiple risk factors for disease.NEW & NOTEWORTHY To our knowledge, this is the first study to comprehensively characterize in vivo sublingual microvascular structure and function (endothelium-dependent and -independent) in healthy patients and those with CVD. Importantly, we used an easy-to-use handheld device that can be easily translated to clinical settings. Our results indicate that baseline microvascular impairments in structure and function can be detected using the CytoCam technology, although reactivity to acetylcholine may be maintained even during disease in the peripheral microcirculation.

Non-invasive assessment of sublingual microcirculation using flow derived from green light PPG: evaluation and reference values.

Significance: The study of sublingual microcirculation offers valuable insights into vascular changes and overcomes some limitations of peripheral microcirculation assessment. Videomicroscopy and pulse oximetry have been used to assess microcirculation, providing insights into organ perfusion beyond macrohemodynamics parameters. However, both techniques have important limitations that preclude their use in clinical practice. Aim: To address this, we propose a non-invasive approach using photoplethysmography (PPG) to assess microcirculation. Approach: Two experiments were performed on different samples of 31 subjects. First, multi-wavelength, finger PPG signals were compared before and while applying pressure on the sensor to determine if PPG signals could detect changes in peripheral microcirculation. For the second experiment, PPG signals were acquired from the ventral region of the tongue, aiming to assess the microcirculation through features calculated from the PPG signal and its first derivative. Results: In experiment 1, 13 out of 15 features extracted from green PPG signals showed significant differences (p<0.05) before and while pressure was applied to the sensor, suggesting that green light could detect flow distortion in superficial capillaries. In experiment 2, 15 features showed potential application of PPG signal for sublingual microcirculation assessment. Conclusions: The PPG signal and its first derivative have the potential to effectively assess microcirculation when measured from the fingertip and the tongue. The assessment of sublingual microcirculation was done through the extraction of 15 features from the green PPG signal and its first derivative. Future studies are needed to standardize and gain a deeper understanding of the evaluated features.

Identifying a sublingual triangle as the ideal site for assessment of sublingual microcirculation.

The sublingual mucosa is a commonly used intraoral location for identifying microcirculatory alterations using handheld vital microscopes (HVMs). The anatomic description of the sublingual cave and its related training have not been adequately introduced. The aim of this study was to introduce anatomy guided sublingual microcirculatory assessment. Measurements were acquired from the floor of the mouth using incident dark-field (IDF) imaging before (T0) and after (T1) sublingual cave anatomy instructed training. Instructions consists of examining a specific region of interested identified through observable anatomical structures adjacent and bilaterally to the lingual frenulum which is next to the sublingual papilla. The anatomical location called the sublingual triangle, was identified as stationed between the lingual frenulum, the sublingual fold and ventrally to the tongue. Small, large, and total vessel density datasets (SVD, LVD and TVD respectively) obtained by non-instructed and instructed measurements (NIN (T0) and IM (T1) respectively) were compared. Microvascular structures were analyzed, and the presence of salivary duct-related microcirculation was identified. A total of 72 video clips were used for analysis in which TVD, but not LVD and SVD, was higher in IM compared to NIM (NIM vs. IM, 25 ± 2 vs. 27 ± 3 mm/mm2 (p = 0.044), LVD NIM vs. IM: 7 ± 1 vs. 8 ± 1mm/mm2 (p = 0.092), SVD NIM vs. IM: 18 ± 2 vs. 20 ± 3 mm/mm2 (p = 0.103)). IM resulted in microcirculatory assessments which included morphological properties such as capillaries, venules and arterioles, without salivary duct-associated microcirculation. The sublingual triangle identified in this study showed consistent network-based microcirculation, without interference from microcirculation associated with specialized anatomic structures. These findings suggest that the sublingual triangle, an anatomy guided location, yielded sublingual based measurements that conforms with international guidelines. IM showed higher TVD values, and future studies are needed with larger sample sizes to prove differences in microcirculatory parameters.

Assessment of the sublingual microcirculation with the GlycoCheck system: Reproducibility and examination conditions.

BACKGROUND: The glycocalyx is an extracellular layer lining the lumen of the vascular endothelium, protecting the endothelium from shear stress and atherosclerosis and contributes to coagulation, immune response and microvascular perfusion. The GlycoCheck system estimates glycocalyx' thickness in vessels under the tongue from perfused boundary region (PBR) and microvascular perfusion (red blood cell (RBC) filling) via a camera and dedicated software. OBJECTIVES: Evaluating reproducibility and influence of examination conditions on measurements with the GlycoCheck system. METHODS: Open, randomised, controlled study including 42 healthy smokers investigating day-to-day, side-of-tongue, inter-investigator variance, intraclass-correlation (ICC) and influence of examination conditions at intervals from 0-180 minutes on PBR and RBC filling. RESULTS: Mean (SD) age was 24.9 (6.1) years, 52% were male. There was no significant intra- or inter-investigator variation for PBR or RBC filling nor for PBR for side-of-tongue. A small day-to-day variance was found for PBR (0.012µm, p = 0.007) and RBC filling (0.003%, p = 0.005) and side-of-tongue, RBC filling (0.025%, p = 0.009). ICC was modest but highly improved by increasing measurements. Small significant influence of cigarette smoking (from 40-180 minutes), high calorie meal intake and coffee consumption was found. The latter two peaking immediately and tapering off but remained significant up to 180 minutes, highest PBR changes for the three being 0.042µm (p<0.05), 0.183µm (p<0.001) and 0.160µm (p<0.05) respectively. CONCLUSIONS: Measurements with the GlycoCheck system have a moderate reproducibility, but highly increases with multiple measurements and a small day-to-day variability. Smoking, meal and coffee intake had effects up to 180 minutes, abstinence is recommended at least 180 minutes before GlycoCheck measurements. Future studies should standardise conditions during measurements.

[An interpretation of the Second consensus on the assessment of sublingual microcirculation in critically ill patients issued by the European Society of Intensive Care Medicine in 2018].

OBJECTIVE: 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.

Rapid clinical assessment of the sublingual microcirculation - Visual scoring using microVAS in comparison to standard semi-automated analysis.

RATIONALE: Alterations in human microcirculation occur in many disease states leading to morbidity and mortality, however assessing the microcirculation is not standard clinical practice. Standard microcirculation analysis using semi-automated analysis is expensive, time consuming, and expertise dependent making it unfeasible. We proposed a novel visual scoring system (microVAS) for the analysis of microcirculation videos that can be performed at the patient bedside in real time. OBJECTIVE: Validate our microVAS score by training health professionals unfamiliar with the microcirculation field to use our microVAS score and compare their scores to the standard method of semi-automated analysis using AVA3 software. METHODS: Using a prospective double-blind study design, we recruited and trained 20 participants to use our microVAS score. Participants scored 40 videos (from 22 healthy and 18 septic patients) for MFI and PPV. The same 40 videos were analysed by an expert using the gold standard semi-automated method of analysis. The results of the participants and the expert were analysed by Pearson's linear regression. Krippendorff's alpha was used to assess inter-rater reliability of the participants. RESULTS: Overall correlation of MFI was r = 0.33 (95% CI 0.27-0.39), p < 0.05; overall correlation of PPV was r = -0.11 (95% CI -0.18 to -0.04), p < 0.05. The Krippendorff's alpha for MFI was 0.56 (healthy videos: α= 0.34, sepsis videos: α= 0.31). For PPV Krippendorff's alpha was 0.43 (healthy videos: α= 0.56, sepsis videos: α= 0.17). CONCLUSIONS: Overall for both MFI and PPV, there was a small correlation between our microVAS score and AVA 3 scores. Regarding inter-rater reliability both MFI and PPV showed fair agreement between raters. Going forward multiple improvements to the microVAS scoring system as well as the training program are suggested to improve reliability and consistency.

Second consensus on the assessment of sublingual microcirculation in critically ill patients: results from a task force of the European Society of Intensive Care Medicine.

PURPOSE: Hand-held vital microscopes (HVMs) were introduced to observe sublingual microcirculatory alterations at the bedside in different shock states in critically ill patients. This consensus aims to provide clinicians with guidelines for practical use and interpretation of the sublingual microcirculation. Furthermore, it aims to promote the integration of routine application of HVM microcirculatory monitoring in conventional hemodynamic monitoring of systemic hemodynamic variables. METHODS: In accordance with the Delphi method we organized three international expert meetings to discuss the various aspects of the technology, physiology, measurements, and clinical utility of HVM sublingual microcirculatory monitoring to formulate this consensus document. A task force from the Cardiovascular Dynamics Section of the European Society of Intensive Care Medicine (with endorsement of its Executive Committee) created this consensus as an update of a previous consensus in 2007. We classified consensus statements as definitions, requirements, and/or recommendations, with a minimum requirement of 80% agreement of all participants. RESULTS: In this consensus the nature of microcirculatory alterations is described. The nature of variables, which can be extracted from analysis of microcirculatory images, is presented and the needed dataset of variables to identify microcirculatory alterations is defined. Practical aspects of sublingual HVM measurements and the nature of artifacts are described. Eleven statements were formulated that pertained to image acquisitions and quality statements. Fourteen statements addressed the analysis of the images, and 13 statements are related to future developments. CONCLUSION: This consensus describes 25 statements regarding the acquisition and interpretation of microcirculatory images needed to guide the assessment of the microcirculation in critically ill patients.

Non-invasive assessment of microvascular dysfunction in patients with microvascular angina.

BACKGROUND: We aimed to evaluate the microvascular function in patients with microvascular angina (MVA) by assessing 1) the endothelial glycocalyx barrier properties using sublingual microscopy, and 2) the myocardial perfusion reserve using cardiovascular magnetic resonance (CMR) imaging. METHODS: Sublingual microscopy was performed in 13 MVA patients (angina pectoris, ST-depression on treadmill testing, normal coronary angiogram) and compared with 2 control groups of 13 volunteers and 14 patients with known obstructive coronary artery disease (CAD). To test the glycocalyx-mediated microvascular responsiveness, the erythrocyte perfused boundary region (PBR) was assessed at baseline and after nitroglycerin challenge. RESULTS: The baseline PBR of MVA patients was similar to controls with CAD (p=0.72), and larger than in volunteers (p=0.02). Only the volunteers demonstrated a significant increase in PBR after nitroglycerin (p=0.03). In the 13 MVA patients, adenosine stress CMR perfusion imaging was performed. Although a significant increase in myocardial perfusion was observed in both the subendocardium and subepicardium during stress, the subendocardial perfusion reserve was significantly lower (p=0.02). The PBR responsiveness of the sublingual microvasculature showed a strong correlation with the transmural myocardial perfusion reserve (r=0.86, p<0.001). CONCLUSIONS: Patients with MVA can be characterized by microvascular glycocalyx dysfunction using sublingual microscopy. The strong correlation between sublingual PBR responsiveness and myocardial perfusion reserve suggests that the glycocalyx may play an important role in the regulation of microvascular volume for myocardial perfusion and supports the concept of impaired glycocalyx barrier properties in MVA.

Protocol for intraoperative assessment of the human cerebrovascular glycocalyx.

INTRODUCTION: Adequate functioning of the blood-brain barrier (BBB) is important for brain homoeostasis and normal neuronal function. Disruption of the BBB has been described in several neurological diseases. Recent reports suggest that an increased permeability of the BBB also contributes to increased seizure susceptibility in patients with epilepsy. The endothelial glycocalyx is coating the luminal side of the endothelium and can be considered as the first barrier of the BBB. We hypothesise that an altered glycocalyx thickness plays a role in the aetiology of temporal lobe epilepsy (TLE), the most common type of epilepsy. Here, we propose a protocol that allows intraoperative assessment of the cerebrovascular glycocalyx thickness in patients with TLE and assess whether its thickness is decreased in patients with TLE when compared with controls. METHODS AND ANALYSIS: This protocol is designed as a prospective observational case-control study in patients who undergo resective brain surgery as treatment for TLE. Control subjects are patients without a history of epileptic seizures, who undergo a craniotomy or burr hole surgery for other indications. Intraoperative glycocalyx thickness measurements of sublingual, cortical and hippocampal microcirculation are performed by video microscopy using sidestream dark-field imaging. Demographic details, seizure characteristics, epilepsy risk factors, intraoperative haemodynamic parameters and histopathological evaluation are additionally recorded. ETHICS AND DISSEMINATION: This protocol has been ethically approved by the local medical ethical committee (ID: NL51594.068.14) and complies with the Declaration of Helsinki and principles of Good Clinical Practice. Informed consent is obtained before study enrolment and only coded data will be stored in a secured database, enabling an audit trail. Results will be submitted to international peer-reviewed journals and presented at international conferences. TRIAL REGISTRATION NUMBER: NTR5568.

Facial mimetic, cosmetic, and functional standardized assessment of the facial artery musculomucosal (FAMM) flap.

OBJECTIVE: To objectively assess donor site morbidity after harvesting the facial artery musculomucosal flap. Use of the FAMM-flap in oral cavity reconstruction remains sporadic. This case series describes our newly developed standardized assessment of this flap in a floor of mouth (FOM) reconstructive setting. METHODS: Standardized postoperative assessment of the FAMM flap for donor site wound complications, functional, facial mimetic and oncologic outcomes. RESULTS: There were no wound complications. Oral competence remained intact, tongue mobility was good to excellent, average word articulation score was 98%, and mimetic function excellent in all patients. Three patients experienced ipsilateral upper lip anesthesia, and five patients were noted to have slight dysfunction of the orbicularis oris resulting in a loss of lip height at rest. CONCLUSION: The FAMM flap is a reliable option for reconstruction of ablative defects of the FOM, and should be considered a workhorse flap for oral cavity defects. Unlike the submental island flap, a complete level I dissection may be concurrently performed without compromising the vascular supply to the FAMM flap.

Safety and feasibility of sublingual microcirculation assessment in the emergency department for civilian and military patients with traumatic haemorrhagic shock: a prospective cohort study.

OBJECTIVES: Sublingual microcirculatory monitoring for traumatic haemorrhagic shock (THS) may predict clinical outcomes better than traditional blood pressure and cardiac output, but is not usually performed until the patient reaches the intensive care unit (ICU), missing earlier data of potential importance. This pilot study assessed for the first time the feasibility and safety of sublingual video-microscopy for THS in the emergency department (ED), and whether it yields useable data for analysis. SETTING: A safety and feasibility assessment was undertaken as part of the prospective observational MICROSHOCK study; sublingual video-microscopy was performed at the UK-led Role 3 medical facility at Camp Bastion, Afghanistan, and in the ED in 3 UK Major Trauma Centres. PARTICIPANTS: There were 15 casualties (2 military, 13 civilian) who presented with traumatic haemorrhagic shock with a median injury severity score of 26. The median age was 41; the majority (n=12) were male. The most common injury mechanism was road traffic accident. PRIMARY AND SECONDARY OUTCOME MEASURES: Safety and feasibility were the primary outcomes, as measured by lack of adverse events or clinical interruptions, and successful acquisition and storage of data. The secondary outcome was the quality of acquired video clips according to validated criteria, in order to determine whether useful data could be obtained in this emergency context. RESULTS: Video-microscopy was successfully performed and stored for analysis for all patients, yielding 161 video clips. There were no adverse events or episodes where clinical management was affected or interrupted. There were 104 (64.6%) video clips from 14 patients of sufficient quality for analysis. CONCLUSIONS: Early sublingual microcirculatory monitoring in the ED for patients with THS is safe and feasible, even in a deployed military setting, and yields videos of satisfactory quality in a high proportion of cases. Further investigations of early microcirculatory behaviour in this context are warranted. TRIAL REGISTRATION NUMBER: NCT02111109.

Microcirculatory assessment of patients under VA-ECMO.

BACKGROUND: Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is an effective technique for providing emergency mechanical circulatory support for patients with cardiogenic shock. VA-ECMO enables a rapid restoration of global systemic organ perfusion, but it has not been found to always show a parallel improvement in the microcirculation. We hypothesized in this study that the response of the microcirculation to the initiation of VA-ECMO might identify patients with increased chances of intensive care unit (ICU) survival. METHODS: Twenty-four patients were included in this study. Sublingual microcirculation measurements were performed using the CytoCam-IDF (incident dark field) imaging device. Microcirculatory measurements were performed at baseline, after VA-ECMO insertion (T1), 48-72 h after initiation of VA-ECMO (T2), 5-6 days after (T3), 9-10 days after (T4), and within 24 h of VA-ECMO removal. RESULTS: Of the 24 patients included in the study population, 15 survived and 9 died while on VA-ECMO. There was no significant difference between the systemic global hemodynamic variables at initiation of VA-ECMO between the survivors and non-survivors. There was, however, a significant difference in the microcirculatory parameters of both small and large vessels at all time points between the survivors and non-survivors. Perfused vessel density (PVD) at baseline (survivor versus non-survivor, 19.21 versus 13.78 mm/mm2, p = 0.001) was able to predict ICU survival on initiation of VA-ECMO; the area under the receiver operating characteristic curve (ROC) was 0.908 (95 % confidence interval 0.772-1.0). CONCLUSION: PVD of the sublingual microcirculation at initiation of VA-ECMO can be used to predict ICU mortality in patients with cardiogenic shock.

Assessment of the appearance, location and morphology of mandibular lingual foramina using cone beam computed tomography.

OBJECTIVES: To investigate the appearance, location and morphology of mandibular lingual foramina (MLF) in the Chinese Han population using cone beam computed tomography (CBCT). METHODS: CBCT images of the mandibular body in 200 patients (103 female patients and 97 male patients, age range 10-70 years) were retrospectively analysed to identify MLF. The canal number, location and direction were assessed. Additionally, the diameter of the lingual foramen, the distance between the alveolar crest and the lingual foramen, the distance between the tooth apex and the lingual foramen and the distance from the mandibular border to the lingual foramen were examined to describe the MLF characteristics. Gender and age differences with respect to foramina were also studied. RESULTS: CBCT can be utilized to visualise lingual foramina. In this study, 683 lingual foramina were detected in 200 CBCT scans, with 538 (78.77%) being ≤1 mm in diameter and 145 (21.23%) being >1 mm. In total, 85.07% of MLF are median lingual canals (MLC) and 14.93% are lateral lingual canals (LLC). Two typical types of lingual foramina were identified according to their relationship with the tooth apex. Most lingual foramina (74.08%) were found below the tooth apex, and those above the tooth apex were much smaller in diameter. Male patients had statistically larger lingual foramina. The distance between the lingual foramen and the tooth apex changed with increasing age. CONCLUSIONS: Determination of the presence, position and size of lingual foramina is important before performing a surgical procedure. Careful implant-prosthetic treatment planning is particularly important in male and/or elderly patients because of the structural characteristics of their lingual foramina.

The Occurrence Rate and Diameter of Arteries Traveling Near the Mandible and an Assessment of the Relative Hemorrhage Risk in Implant Surgery.

BACKGROUND: Bleeding in the floor of the mouth during implant surgery is attributed to arterial injuries in the sublingual space. PURPOSE: This study aimed to assess the relative hemorrhage risk during implant surgery. MATERIALS AND METHODS: We investigated the occurrence rate and diameter of submental and sublingual arteries with special reference to their relationship with the course patterns of these arteries using 26 human cadavers. RESULTS: Three types of arteries were distinguished: main duct (MD), mucoperiosteal branches (MB), and cortical branches (CB). The occurrence rate of MB and CB was significantly high at the central incisor region in the upper part of the mylohyoid muscle, whereas the diameter of the MB and CB was significantly smaller than the occurrence rate of MD at the incisor regions. The occurrence rate of MD in the submental artery was significantly higher at the lateral incisor, canine, and premolar regions in the lower parts, whereas the occurrence rate of MD was significantly lower at the second and third molars in the upper parts. CONCLUSION: The susceptibility of the submental artery to injury is suggested at the incisors, canine, premolars, and first molar regions during implant surgery.

Histologic assessment of tumor budding in preoperative biopsies to predict nodal metastasis in squamous cell carcinoma of the tongue and floor of the mouth.

BACKGROUND: In squamous cell carcinoma (SCC) of the tongue and the floor of the mouth (FOM), it is important to predict lymph node metastasis, including occult metastasis, before operating. The purpose of this study was for us to determine practical histopathologic parameters as predictive factors for lymph node metastasis in preoperative SCC biopsy specimens. METHODS: We examined 91 cases of SCC for conventional histopathologic assessment and a new factor, tumor budding, and their relationship with lymph node metastasis. RESULTS: Significant factors via univariate analysis (p < .01) were budding (score ≥3) and tumor depth (≥3 mm) and these were associated with lymph node metastasis. Moreover, both budding and tumor depth significantly correlated with relapse-free survival; however, evaluating biopsy specimens often proved inaccurate for predicting true tumor depth of cancer invasion. CONCLUSION: Tumor budding using immunohistochemistry for cytokeratin should be added to routine histologic assessments as a new criterion factoring into the decision as to whether neck dissection is indicated. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1582-E1590, 2016.

Evaluación anatómica del piso de boca mediante resonancia magnética / Floor of mouth anatomical assessment by magnetic resonance

El presente artículo de revisión fue realizado para reconocer las estructuras anatómicas del piso de boca mediante imágenes de resonancia magnética; esta es una de las regiones más delicadas de la cavidad oral, constituida solamente por tejidos blandos, muchos de ellos vasculares, glandulares y nerviosos, carece de reparos anatómicos óseos siendo susceptible a patologías que deben ser diagnosticadas por el estomatólogo. Se considera a la resonancia magnética el estudio de elección para los tejidos blandos pues permite conocer la anatomía, límites y contenido presentes en el piso de boca; sin embargo su uso es óptimo cuando se requiera evaluar el disco articular. El presente trabajo consistió en una revisión bibliográfica mediante búsqueda de artículos en bases de datos e internet. La resonancia magnética es útil porque evita las radiaciones ionizantes, se puede aplicar en la mayoría de los casos excepto cuando existan elementos ferromagnéticos. Dicha técnica es adecuada para el estudio de la anatomía del piso de boca, a pesar de existir algún grado de dificultad en la interpretación es considerada por los radiólogos como la prueba diagnóstica del futuro...

To recognize anatomical structures mouth floor by magnetic resonance imaging is one of the most sensitive regions of the oral cavity, constituted only by soft tissues, many vascular and nervous secretory lacks bony anatomic landmarks being susceptible to diseases to be diagnosed by the dentist. It considers MRI study of choice for soft tissue because it allows to know the anatomy, boundaries and content present on the floor of mouth; however its use is optimal when required to assess the articular disc. We conducted a literature review using search in databases and Internet. MRI is useful because it prevents ionizing radiation, can be applied in most cases unless there are ferromagnetic elements. This technique is suitable for the study of the anatomy of the floor of the mouth, although there is some difficulty in interpretation is considered by radiologists as the diagnostic test of the future...

New insights into systemic sclerosis related microcirculatory dysfunction by assessment of sublingual micr\ocirculation and vascular glycocalyx layer. Results from a preliminary study.

BACKGROUND: Initial morphological and functional markers of systemic sclerosis (SSc) are evidenced in microvascular structural damage. However, nailfold videocapillaroscopy (NVC) explores only morphological abnormalities. Sidestream Dark Field (SDF) imaging of sublingual microcirculation enables assessment of both morphological and functional capillary impairment and allows measurement of the glycocalyx layer, which is an indicator of endothelial dysfunction. OBJECTIVE: To describe and validate sublingual abnormalities assessed by SDF device in comparison with NVC findings and to measure the thickness of the glycocalyx layer. METHODS: From February to May 2014, 26 subjects (16 SSc patients and 10 healthy controls) underwent standardised NVC and SDF imaging of sublingual microcirculation. Glycocalyx thickness was also measured. RESULTS: Capillary density and percentage of perfused vessels were significantly reduced in patients with SSc (n = 13) compared to controls. Correlation between nailfold capillary density assessed by NVC and sublingual capillary density assessed by SDF was observed (r(2) = 0.59; P = 0.023). According to the NVC pattern, patients with "active" disease experienced greater reduction in capillary density than patients with "late" disease as suggested by the de Backer score (9.17 ± 0.81 vs 10.86 ± 1.19; P = 0.03). Additionally, the decrease in glycocalyx thickness was measured in SSc patients (n = 13) compared to controls (n = 10) (0.41 ± 0.03 versus 0.76 ± 0.29 P = 0.003). CONCLUSION: Our results suggest for the first time in SSc, that sublingual microcirculation and glycocalyx are impaired and that SDF imaging findings correlate with those of NVC. Nevertheless, further studies are required for the validation of our preliminary results.

Midline submental intubation might be the preferred alternative to oral and nasal intubation in elective oral and craniomaxillofacial surgery when indicated.

PURPOSE: No consensus exists to date regarding the best method of controlling the airway for oral or craniomaxillofacial surgery when orotracheal and nasotracheal intubations are unsuccessful or contraindicated. The most commonly used method of tracheostomy has been associated with a high degree of morbidity. Therefore, the present study was conducted to determine the indications, safety, efficacy, time required, drawbacks, complications, and costs of the midline submental intubation (SMI) approach in elective oral and craniomaxillofacial surgical procedures. MATERIALS AND METHODS: A retrospective case series study was used to evaluate the surgical, financial, and photographic records of all patients who had undergone oral or craniomaxillofacial operations at Sharda University School of Dental Sciences, Greater Noida, from April 2006 to March 2014. The indications, drawbacks, time required for the procedure, ability to provide a secure airway, intra- and postoperative complications, and additional costs associated with SMI were analyzed. RESULTS: Of the 2,823 patients treated, the present study included 120 patients (97 men and 23 women, aged 19 to 60 years). The average time required for SMI was 10 ± 2 minutes. No episode of intraoperative oxygen desaturation was noted. One intraoperative complication, an injury to the ventral surface of the tongue, was encountered. Two patients developed infection at the skin incision site. No significant additional cost was incurred with the use of SMI. CONCLUSIONS: SMI has been successfully used in elective oral and craniomaxillofacial surgical procedures for which oral and nasal intubations were either not indicated or not possible. The advantages include a quick procedure, insignificant complications, the ability to provide a stable airway, and no added costs, making SMI a quick, safe, efficient, and cost-effective alternative in such cases.

[An automated method for assessment of sublingual microcirculatory perfusion based on videos].

OBJECTIVE: The assessment result of microcirculatory perfusion provides significant evidence for the detection of microcirculatory alterations in sepsis patients, and functional capillary density based on vessel segmentation can reflect microcirculatory perfusion effectively. METHODS: First, preprocessing comprise operations to improve the quality of images in order to maximize the contrast between background and vessels. Secondly, adaptive local thresholding is used for initial segmentation to get the general vessel region. Finally, post-processing technique reduces the image artifacts and links the vessel fragment, and then functional capillary density is calculated based on the segmentation results. RESULTS: Several sublingual microcirculatory data have been tested, and the agreement between the results by AVA and the proposed algorithm reached up to 92%. CONCLUSIONS: The method can realize automated assessment of sublingual microcirculatory perfusion rapidly and accurately, and has strong clinical value.

Sublingual ultrasound as an assessment method for predicting difficult intubation: a pilot study.

Current methods to assess the airway before tracheal intubation are variable in their ability to predict a difficult airway accurately. We hypothesised that sublingual ultrasound could provide additional information to predict a difficult airway with greater success than current methods. We recruited 110 patients to perform sublingual ultrasound on themselves following brief instruction. Ability to view the hyoid bone on sublingual ultrasound, mouth opening distance, thyromental distance, neck mobility, size of mandible and modified Mallampati classification were recorded and assessed for ability to predict a difficult intubation based on the grade of laryngoscope. Visibility of the hyoid using ultrasound was associated with a laryngoscopic grade of 1-2 (p < 0.0001), and (p < 0.0001) had a positive likelihood ratio of 21.6 and a negative likelihood ratio of 0.28. Each of the other methods had considerably lower positive likelihood ratios and lower sensitivity. Our results suggest that sublingual ultrasound is a potential tool for predicting a difficult airway in addition to conventional methods.