Early Detection of Complete Vascular Occlusion in a Pedicle Flap Model Using Quantitation Spectral Imaging

Department of Surgery, University of California, Irvine, Irvine, California, United States
Plastic and Reconstructive Surgery (Impact Factor: 3.33). 12/2010; 126(6):1924-35. DOI: 10.1097/PRS.0b013e3181f447ac
Source: PubMed

ABSTRACT Vascular occlusion after tissue transfer is a devastating complication that can lead to complete flap loss. Spatial frequency domain imaging is a new, noncontact, noninvasive, wide-field imaging technology capable of quantifying oxygenated and deoxygenated hemoglobin levels, total hemoglobin, and tissue saturation.
Pedicled fasciocutaneous flaps on Wistar rats (400 to 500 g) were created and underwent continuous imaging using spatial frequency domain imaging before and after selective vascular occlusion. Three flap groups (control, selective arterial occlusion, and selective venous occlusion) and a fourth group composed of native skin between the flaps were measured.
There were no statistically significant differences between the control flap group and the experimental flap groups before selective vascular occlusion: oxyhemoglobin (p=0.2017), deoxyhemoglobin (p=0.3145), total hemoglobin (p=0.2718), and tissue saturation, (p=0.0777). In the selective arterial occlusion flap group, percentage change in total hemoglobin was statistically different from that of the control flap group (p=0.0218). The remaining parameters were not statistically different from those of the control flap: percentage change in oxyhemoglobin (p=0.0888), percentage change in deoxyhemoglobin (p=0.5198), and percentage change in tissue saturation (p=0.4220). The selective venous occlusion flap group demonstrated changes statistically different compared with the control flap group: percentage change in oxyhemoglobin (p=0.0029) and deoxyhemoglobin, total hemoglobin, and tissue saturation (p<0.0001).
Spatial frequency domain imaging provides two-dimensional, spatially resolved maps of tissue oxyhemoglobin, deoxyhemoglobin, total hemoglobin, and tissue saturation. Results presented here indicate that this can be used to quantify and detect physiologic changes that occur after arterial and venous occlusion in a rodent tissue transfer flap model. This portable, noncontact, noninvasive device may have a high clinical applicability in monitoring postoperative patients.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: INTRODUÇÃO: A monitorização do retalho livre após a cirurgia é de vital importância, especialmente nas primeiras horas de pós-operatório, pois o momento de reabordagem pode ser o definidor entre o salvamento ou a perda do retalho. Até o momento, não existe trabalho na literatura estudando a decisão de abordagem do retalho baseada em medidas objetivas ou a comparação da glicemia entre retalhos que evoluíram bem com os que sofreram sofrimento vascular. O objetivo deste estudo é avaliar a validade da medida da glicemia capilar do retalho como método de monitorização de retalhos microcirúrgicos comparando com a avaliação clínica. MÉTODO: Foram estudados prospectivamente 16 pacientes portadores de retalhos livres, realizados de maio de 2012 a julho de 2012. A glicemia capilar foi avaliada por equipe formada por profissionais não envolvidos com a cirurgia realizada. A avaliação clínica do retalho foi realizada no pós-operatório imediato, na chegada à UTI, a cada 3 horas e sempre que necessário. RESULTADOS: Dos 16 pacientes, 5 (31,3%) apresentaram complicações nas primeiras 24 horas. Todas as complicações observadas foram trombose venosa. Foi observada diferença estatisticamente significante na glicemia capilar de portadores de retalhos que apresentaram trombose venosa em comparação àqueles que não tiveram a complicação, nas medidas realizadas 6 horas, 9 horas e 12 horas após a operação (P < 0,05). CONCLUSÕES: A medida da glicemia capilar não foi superior à avaliação clínica por profissional experiente na detecção de trombose venosa de retalhos livres.
    12/2012; 27(4):523-526. DOI:10.1590/S1983-51752012000400008
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Accurate and timely assessment of burn wound severity is a critical component of wound management and has implications related to course of treatment. While most superficial burns and full thickness burns are easily diagnosed through visual inspection, burns that fall between these extremes are challenging to classify based on clinical appearance. Because of this, appropriate burn management may be delayed, increasing the risk of scarring and infection. Here we present an investigation that employs spatial frequency domain imaging (SFDI) and laser speckle imaging (LSI) as non-invasive technologies to characterize in-vivo burn severity. We used SFDI and LSI to investigate controlled burn wounds of graded severity in a Yorkshire pig model. Burn wounds were imaged starting at one hour after the initial injury and daily at approximately 24, 48 and 72 hours post burn. Biopsies were taken on each day in order to correlate the imaging data to the extent of burn damage as indicated via histological analysis. Changes in reduced scattering coefficient and blood flow could be used to categorize burn severity as soon as one hour after the burn injury. The results of this study suggest that SFDI and LSI information have the potential to provide useful metrics for quantifying the extent and severity of burn injuries.
    Biomedical Optics Express 10/2014; 5(10). DOI:10.1364/BOE.5.003467 · 3.50 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The ability to phenotype wounds for the purposes of assessing severity, healing potential and treatment is an important function of evidence-based medicine. A variety of optical technologies are currently in development for noninvasive wound assessment. To varying extents, these optical technologies have the potential to supplement traditional clinical wound evaluation and research, by providing detailed information regarding skin components imperceptible to visual inspection. These assessments are achieved through quantitative optical analysis of tissue characteristics including blood flow, collagen remodeling, hemoglobin content, inflammation, temperature, vascular structure and water content. Technologies that have, to this date, been applied to wound assessment include: near infrared imaging, thermal imaging, optical coherence tomography, orthogonal polarization spectral imaging, fluorescence imaging, laser Doppler imaging, microscopy, spatial frequency domain imaging, photoacoustic detection, and spectral/hyperspectral imaging. We present a review of the technologies in use or development for these purposes with three aims: 1) providing basic explanations of imaging technology concepts, 2) reviewing the wound imaging literature, and 3) providing insight into areas for further application and exploration. Noninvasive imaging is a promising advancement in wound assessment and all technologies require further validation. This article is protected by copyright. All rights reserved. © 2015 by the Wound Healing Society.
    Wound Repair and Regeneration 04/2015; DOI:10.1111/wrr.12262 · 2.77 Impact Factor