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Clinical Oral Investigations Sep 2023Postoperative flap monitoring is essential in oral microvascular reconstruction for timely detection of vascular compromise. This study investigated the use of attached...
OBJECTIVES
Postoperative flap monitoring is essential in oral microvascular reconstruction for timely detection of vascular compromise. This study investigated the use of attached surface probes for the oxygen-2-see (O2C) analysis system (LEA Medizintechnik, Germany) for intraoral flap perfusion monitoring.
MATERIALS AND METHODS
The study included 30 patients who underwent oral reconstruction with a microvascular radial-free forearm flap (RFFF) or anterolateral thigh flap (ALTF) between 2020 and 2022. Flap perfusion was measured with attached (3-mm measurement depth) and unattached surface probes (2- and 8-mm measurement depths) for the O2C analysis system at 0, 12, 24, 36, and 48 h postoperatively. Flap perfusion monitoring with attached surface probes was evaluated for cut-off values for flap blood flow, hemoglobin concentration, and hemoglobin oxygen saturation indicative of vascular compromise and for accuracy and concordance with unattached surface probes.
RESULTS
Three RFFFs were successfully revised, and one ALTF was unsuccessfully revised. The cut-off values indicative of vascular compromise for flap perfusion monitoring with attached surface probes were for RFFF and ALTF: blood flow < 60 arbitrary units (AU) and < 40AU, hemoglobin concentration > 100AU and > 80AU (both > 10% increase), and hemoglobin oxygen saturation < 40% and < 30%. Flap perfusion monitoring with attached surface probes yielded a 97.1% accuracy and a Cohen's kappa of 0.653 (p < 0.001).
CONCLUSIONS
Flap perfusion monitoring with attached surface probes for the O2C analysis system detected vascular compromise accurately and concordantly with unattached surface probes.
CLINICAL RELEVANCE
Attached surface probes for the O2C analysis system are a feasible option for intraoral flap perfusion monitoring.
Topics: Humans; Plastic Surgery Procedures; Surgical Flaps; Mouth; Perfusion; Hemoglobins; Free Tissue Flaps
PubMed: 37522990
DOI: 10.1007/s00784-023-05177-x -
BMC Surgery Aug 2023Real-time quantification of tissue perfusion can improve intraoperative surgical decision making. Here we demonstrate the utility of Laser Speckle Contrast Imaging as an...
BACKGROUND/PURPOSE
Real-time quantification of tissue perfusion can improve intraoperative surgical decision making. Here we demonstrate the utility of Laser Speckle Contrast Imaging as an intra-operative tool that quantifies real-time regional differences in intestinal perfusion and distinguishes ischemic changes resulting from arterial/venous obstruction.
METHODS
Porcine models (n = 3) consisted of selectively devascularized small bowel loops that were used to measure the perfusion responses under conditions of control/no vascular occlusion, arterial inflow occlusion, and venous outflow occlusion using laser speckle imaging and indocyanine green fluoroscopy. Laser Speckle was also used to assess perfusion differences between small bowel antimesenteric-antimesenteric and mesenteric-mesenteric anastomoses. Perfusion quantification was measured in relative perfusion units calculated from the laser speckle perfusion heatmap.
RESULTS
Laser Speckle distinguished between visually identified perfused, watershed, and ischemic intestinal segments with both color heatmap and quantification (p < .00001). It detected a continuous gradient of relative intestinal perfusion as a function of distance from the stapled ischemic bowel edge. Strong positive linear correlation between relative perfusion units and changes in mean arterial pressure resulting from both arterial (R = .96/.79) and venous pressure changes (R = .86/.96) was observed. Furthermore, Laser Speckle showed that the antimesenteric anastomosis had a higher perfusion than mesenteric anastomosis (p < 0.01).
CONCLUSIONS
Laser Speckle Contrast Imaging provides objective, quantifiable tissue perfusion information in both color heatmap and relative numerical units. Laser Speckle can detect spatial/temporal differences in perfusion between antimesenteric and mesenteric borders of a bowel segment and precisely detect perfusion changes induced by progressive arterial/venous occlusions in real-time.
Topics: Swine; Animals; Laser Speckle Contrast Imaging; Perfusion; Intestines; Laparoscopy; Arteries; Vascular Diseases
PubMed: 37649010
DOI: 10.1186/s12893-023-02161-w -
Liver Transplantation : Official... Dec 2023
Topics: Humans; Liver Transplantation; Perfusion; Tissue and Organ Procurement; Organ Preservation; Tissue Donors; Death
PubMed: 37540165
DOI: 10.1097/LVT.0000000000000236 -
Journal of the American College of... Oct 2023
Topics: Humans; Heart Transplantation; Tissue and Organ Procurement; Cardiovascular System; Perfusion; Tissue Donors; Death; Graft Survival
PubMed: 37793749
DOI: 10.1016/j.jacc.2023.08.025 -
Archives of Cardiovascular Diseases 2023Residual lesions following Fallot repair are primarily pulmonary regurgitation and right ventricular outflow tract obstruction. These lesions may impact exercise...
BACKGROUND
Residual lesions following Fallot repair are primarily pulmonary regurgitation and right ventricular outflow tract obstruction. These lesions may impact exercise tolerance, particularly because of a poor increase in left ventricular stroke volume. Pulmonary perfusion imbalance is also common, but its effect on cardiac adaptation to exercise is not known.
AIM
To assess the association between pulmonary perfusion asymmetry and peak indexed exercise stroke volume (pSVi) in young patients.
METHODS
We retrospectively studied 82 consecutive patients with Fallot repair (mean age 15.2±3.8 years) who underwent echocardiography, four-dimensional flow magnetic resonance imaging and cardiopulmonary testing with pSVi measurement by thoracic bioimpedance. Normal pulmonary flow distribution was defined as right pulmonary artery perfusion between 43 and 61%.
RESULTS
Normal, rightward and leftward flow distributions were found in 52 (63%), 26 (32%) and four (5%) patients, respectively. Independent predictors of pSVi were right pulmonary artery perfusion (β=0.368, 95% confidence interval [CI] 0.188 to 0.548; P=0.0003), right ventricular ejection fraction (β=0.205, 95% CI 0.026 to 0.383; P=0.049), pulmonary regurgitation fraction (β=-0.283, 95% CI -0.495 to -0.072; P=0.006) and Fallot variant with pulmonary atresia (β=-0.213, 95% CI -0.416 to -0.009; P=0.041). The pSVi prediction was similar when the categorical variable right pulmonary artery perfusion>61% was used (β=0.210, 95% CI 0.006 to 0.415; P=0.044).
CONCLUSION
In addition to right ventricular ejection fraction, pulmonary regurgitation fraction and Fallot variant with pulmonary atresia, right pulmonary artery perfusion is a predictor of pSVi, in that rightward imbalanced pulmonary perfusion favours greater pSVi.
Topics: Humans; Child; Adolescent; Young Adult; Adult; Stroke Volume; Tetralogy of Fallot; Pulmonary Valve Insufficiency; Retrospective Studies; Pulmonary Atresia; Ventricular Function, Right; Perfusion
PubMed: 37422422
DOI: 10.1016/j.acvd.2023.06.002 -
BMC Pulmonary Medicine Jan 2024Pulmonary air embolism (AE) and thromboembolism lead to severe ventilation-perfusion defects. The spatial distribution of pulmonary perfusion dysfunctions differs...
BACKGROUND
Pulmonary air embolism (AE) and thromboembolism lead to severe ventilation-perfusion defects. The spatial distribution of pulmonary perfusion dysfunctions differs substantially in the two pulmonary embolism pathologies, and the effects on respiratory mechanics, gas exchange, and ventilation-perfusion match have not been compared within a study. Therefore, we compared changes in indices reflecting airway and respiratory tissue mechanics, gas exchange, and capnography when pulmonary embolism was induced by venous injection of air as a model of gas embolism or by clamping the main pulmonary artery to mimic severe thromboembolism.
METHODS
Anesthetized and mechanically ventilated rats (n = 9) were measured under baseline conditions after inducing pulmonary AE by injecting 0.1 mL air into the femoral vein and after occluding the left pulmonary artery (LPAO). Changes in mechanical parameters were assessed by forced oscillations to measure airway resistance, lung tissue damping, and elastance. The arterial partial pressures of oxygen (PaO) and carbon dioxide (PaCO) were determined by blood gas analyses. Gas exchange indices were also assessed by measuring end-tidal CO concentration (ETCO), shape factors, and dead space parameters by volumetric capnography.
RESULTS
In the presence of a uniform decrease in ETCO in the two embolism models, marked elevations in the bronchial tone and compromised lung tissue mechanics were noted after LPAO, whereas AE did not affect lung mechanics. Conversely, only AE deteriorated PaO, and PaCO, while LPAO did not affect these outcomes. Neither AE nor LPAO caused changes in the anatomical or physiological dead space, while both embolism models resulted in elevated alveolar dead space indices incorporating intrapulmonary shunting.
CONCLUSIONS
Our findings indicate that severe focal hypocapnia following LPAO triggers bronchoconstriction redirecting airflow to well-perfused lung areas, thereby maintaining normal oxygenation, and the CO elimination ability of the lungs. However, hypocapnia in diffuse pulmonary perfusion after AE may not reach the threshold level to induce lung mechanical changes; thus, the compensatory mechanisms to match ventilation to perfusion are activated less effectively.
Topics: Animals; Rats; Carbon Dioxide; Hypocapnia; Thromboembolism; Perfusion; Pulmonary Embolism; Bronchi; Embolism, Air; Bronchoconstriction
PubMed: 38200483
DOI: 10.1186/s12890-024-02842-z -
The Journal of Hand Surgery Feb 2024Timely and accurate triage of upper extremity injuries is critical, but current perfusion monitoring technologies have shortcomings. These limitations are especially...
PURPOSE
Timely and accurate triage of upper extremity injuries is critical, but current perfusion monitoring technologies have shortcomings. These limitations are especially pronounced in patients with darker skin tones. This pilot study evaluates a Eulerian Video Magnification (EVM) algorithm combined with color channel waveform extraction to enable video-based measurement of hand and finger perfusion.
METHODS
Videos of 10 volunteer study participants with Fitzpatrick skin types III-VI were taken in a controlled environment during normal perfusion and tourniquet-induced ischemia. Videos were EVM processed, and red/green/blue color channel characteristics were extracted to produce waveforms. These videos were assessed by surgeons with a range of expertise in hand injuries. The videos were randomized and presented in 1 of 3 ways: unprocessed, EVM processed, and EVM with waveform output (EVM+waveform). Survey respondents indicated whether the video showed an ischemic or perfused hand or if they were unable to tell. We used group comparisons to evaluate response accuracy across video types, skin tones, and respondent groups.
RESULTS
Of the 51 providers to whom the surveys were sent, 25 (49%) completed them. Using the Pearson χ test, the frequencies of correct responses were significantly higher in the EVM+waveform category than in the unprocessed or EVM videos. Additionally, the agreement was higher among responses to the EVM+waveform questions than among responses to the unprocessed or EVM processed. The accuracy and agreement from the EVM+waveform group were consistent across all skin pigmentations evaluated.
CONCLUSIONS
Video-based EVM processing combined with waveform extraction from color channels improved the surgeon's ability to identify tourniquet-induced finger ischemia via video across all skin types tested.
CLINICAL RELEVANCE
Eulerian Video Magnification with waveform extraction improved the assessment of perfusion in the distal upper extremity and has potential future applications, including triage, postsurgery vascular assessment, and telemedicine.
Topics: Humans; Pilot Projects; Upper Extremity; Hand; Perfusion; Ischemia; Video Recording
PubMed: 35963795
DOI: 10.1016/j.jhsa.2022.06.022 -
JAMA Oct 2023
Topics: Humans; Perfusion; Temperature; Tissue and Organ Procurement; Body Temperature
PubMed: 37815568
DOI: 10.1001/jama.2023.16890 -
JAMA Oct 2023
Topics: Humans; Body Temperature; Perfusion; Temperature; Tissue and Organ Procurement
PubMed: 37815571
DOI: 10.1001/jama.2023.16887 -
JAMA Oct 2023
Topics: Humans; Perfusion; Tissue and Organ Procurement; Temperature; Body Temperature
PubMed: 37815572
DOI: 10.1001/jama.2023.16884