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Etra JW, Fidder SAJ, Frost CM, Messner F, Guo Y, Vasilic D, Beck SE, Bonawitz S, Brandacher G, Cooney DS. Latissimus Dorsi Myocutaneous Flap Procedure in a Swine Model. J INVEST SURG 2020; 34:1289-1296. [PMID: 32752901 DOI: 10.1080/08941939.2020.1795952] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
BACKGROUND As surgical research expands in both breadth and scope, translational models become increasingly important. The accessibility, reproducibility, and clinical applicability of translational models is of vital importance to ensure adequate and accurate research. Though different flap models have been described, the literature lacks an in-depth, technical description of an easy large-animal preclinical model. We here describe the procedure for elevation of a latissimus dorsi flap in a swine. This flap contains muscle and skin that can be isolated on a vascular pedicle, transferred as a free flap, perfused, or innervated/denervated as dictated by the needs of the experiment. METHODS Five different latissimus dorsi flaps were elevated in miniature swine. Careful attention was paid to anatomical landmarks and optimal placement of incision, dissection, and retraction. Temporary ischemia with vascular clamping was performed along with serial digital and infrared imaging both intra- and postoperatively. In three of the flaps with induced ischemia, the animal was observed for a 30-day follow up with daily photodocumentation and intermittent biopsy. RESULTS A reproducible latissimus flap model was designed with optimized conditions. In the animals in which flaps were followed postoperatively, complete healing was seen within 30 days without evidence of procedure-related ischemia or loss of motor function. CONCLUSION We have identified and described a pre-clinical large animal flap model that can be easily reproduced for translational studies of multiple scientific areas including flap-based repair, ischemia, ischemia reperfusion, and operative technique. This provides an important model for ready replication in preclinical studies of many varieties.
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Affiliation(s)
- Joanna W Etra
- Department of Plastic and Reconstructive Surgery, Vascularized Composite Allotransplantation (VCA) Laboratory, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA.,Department of Surgery, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Samuel A J Fidder
- Department of Plastic and Reconstructive Surgery, Vascularized Composite Allotransplantation (VCA) Laboratory, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA.,Department of Plastic and Reconstructive Surgery, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Christopher M Frost
- Department of Plastic and Reconstructive Surgery, Vascularized Composite Allotransplantation (VCA) Laboratory, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Franka Messner
- Department of Plastic and Reconstructive Surgery, Vascularized Composite Allotransplantation (VCA) Laboratory, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Yinan Guo
- Department of Plastic and Reconstructive Surgery, Vascularized Composite Allotransplantation (VCA) Laboratory, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA.,Department of Hand and Microsurgery, Xiangya Hospital, Central South University, Hunan, China
| | - Dalibor Vasilic
- Department of Plastic and Reconstructive Surgery, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Sarah E Beck
- Department of Molecular and Comparative Pathobiology, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Steven Bonawitz
- Department of Surgery, Cooper Medical School, Rowan University, Camden, New Jersey, USA
| | - Gerald Brandacher
- Department of Plastic and Reconstructive Surgery, Vascularized Composite Allotransplantation (VCA) Laboratory, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Damon S Cooney
- Department of Plastic and Reconstructive Surgery, Vascularized Composite Allotransplantation (VCA) Laboratory, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA
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Paparde A, Nēringa-Martinsone K, Plakane L, Aivars JI. Nail fold capillary diameter changes in acute systemic hypoxia. Microvasc Res 2014; 93:30-3. [PMID: 24607833 DOI: 10.1016/j.mvr.2014.02.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 02/23/2014] [Accepted: 02/26/2014] [Indexed: 02/07/2023]
Abstract
The present study was undertaken to determine the effect of arterial blood hypoxemia induced by acute systemic hypoxia (pO2=12%) on capillary recruitment and diameter, and red blood cell (RBC) velocity in human nail fold capillaries during rest, arterial post-occlusive reactive hyperemia (PRH), and venous occlusion (VO) using intravital video-capillaroscopy. Capillary recruitment was unchanged in acute systemic hypoxia (H) versus normoxia (N). There was no difference in RBC velocity measurements between normoxia and hypoxia (P<0.63). However, a statistically significant increase in nail fold capillary total width (N, 39.9±9.1 vs. H, 42.7±10.3 μm; P<0.05), apical diameter (N, 15.5±4.3 vs. H, 16.8±4.3 μm; P<0.05), arterial diameter (N, 11.9±3.5 vs. H, 13.9±4.1 μm; P<0.05), and venous diameter (N, 15.5±4.3 vs. H, 17.2±4.8 μm; P<0.05) was observed and continued to be significant most often during post-occlusive reactive hyperemia (PRH) and venous congestion (VO). These data suggest that acute systemic hypoxia does not increase capillary recruitment, but instead increases capillary diameter, resulting in increased capillary blood flow.
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Affiliation(s)
- Artūrs Paparde
- University of Latvia Faculty of Biology, Department of Human and Animal Physiology, Latvia; University of Latvia Institute of Experimental and Clinical Medicine, Latvia.
| | | | - Līga Plakane
- University of Latvia Faculty of Biology, Department of Human and Animal Physiology, Latvia; University of Latvia Institute of Experimental and Clinical Medicine, Latvia
| | - Juris Imants Aivars
- University of Latvia Faculty of Biology, Department of Human and Animal Physiology, Latvia
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WAELGAARD L, DAHL BM, KVARSTEIN G, TØNNESSEN TI. Tissue gas tensions and tissue metabolites for detection of organ hypoperfusion and ischemia. Acta Anaesthesiol Scand 2012; 56:200-9. [PMID: 22103593 DOI: 10.1111/j.1399-6576.2011.02572.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/07/2011] [Indexed: 12/30/2022]
Abstract
BACKGROUND The aim of this study was to evaluate how tissue gas tensions and tissue metabolites measured in situ can detect hypoperfusion and differentiate between aerobic and anaerobic conditions during hemorrhagic shock. We hypothesized that tissue PCO(2) (PtCO(2)) would detect hypoperfusion also under aerobic conditions and detect anaerobic metabolism concomitantly with or earlier than other markers. METHODS Prospective experimental animal study with eight anesthetized pigs subjected to a continuous blood loss ∼8% of total blood volume per hour until death. We measured cardiac index, organ blood flows, and tissue levels of PO(2), PCO(2), glucose, pyruvate, lactate, and glycerol in intestine, liver, kidney, and skeletal muscle. RESULTS With reduction in blood flow to the organs under aerobic conditions, PtCO(2) increased ∼1-4 kPa from baseline. With the onset of tissue hypoxia there was a pronounced increase of PtCO(2), lactate, lactate-pyruvate (LP) ratio, and glycerol. Tissue pH and bicarbonate decreased significantly, indicating that metabolic acid was buffered by bicarbonate to generate CO(2). CONCLUSION Moderate tissue hypoperfusion under aerobic conditions is associated with increased PtCO(2), in contrast to metabolic parameters of ischemia (lactate, LP ratio, and glycerol) which remain low. From the onset of ischemia there is a much more rapid and pronounced increase in PtCO(2), lactate, and LP ratio. PtCO(2) can be used as a marker of hypoperfusion under both aerobic and anaerobic conditions; it gives an earlier warning of hypoperfusion than metabolic markers and increases concomitantly with or earlier than other markers at the onset of tissue anaerobiosis.
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Affiliation(s)
- L. WAELGAARD
- The Acute Clinic; Department of Anesthesiology and Critical Care Medicine; Oslo University Hospital; Oslo; Norway
| | - B. M. DAHL
- The Intervention Centre; Oslo University Hospital; Oslo; Norway
| | - G. KVARSTEIN
- The Acute Clinic; Department of Anesthesiology and Critical Care Medicine; Oslo University Hospital; Oslo; Norway
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Arbogast S, Reid MB. Oxidant activity in skeletal muscle fibers is influenced by temperature, CO2 level, and muscle-derived nitric oxide. Am J Physiol Regul Integr Comp Physiol 2004; 287:R698-705. [PMID: 15178539 DOI: 10.1152/ajpregu.00072.2004] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Free radicals are produced continuously by skeletal muscle fibers. Extracellular release of reactive oxygen species (ROS) and nitric oxide (NO) derivatives has been demonstrated, but little is known about intracellular oxidant regulation. We used a fluorescent oxidant probe, 2',7'-dichlorofluorescin (DCFH), to assess net oxidant activity in passive muscle fiber bundles isolated from mouse diaphragm and studied in vitro. We tested the following three hypotheses. 1) Net oxidant activity is decreased by muscle cooling. 2) CO(2) exposure depresses intracellular oxidant activity. 3) Muscle-derived ROS and NO both contribute to overall oxidant activity. Our results indicate that DCFH oxidation was diminished by cooling muscle fibers from 37 degrees C to 23 degrees C (P < 0.001). The rate of DCFH oxidation correlated positively with CO(2) exposure (0-10%; P < 0.05) and negatively with concurrent changes in pH (7.0-8.5; P < 0.05). Separate exposures to anti-ROS enzymes (superoxide dismutase, 1 kU/ml; catalase, 1 kU/ml), a glutathione peroxidase mimetic (ebselen, 30 microM), NO synthase inhibitors (N(omega)-nitro-l-arginine methyl ester, 1 mM; N(omega)-monomethyl-l-arginine, 1 mM), or an NO scavenger (hemoglobin, 1 microM) each inhibited DCFH oxidation (P < 0.05). Oxidation was increased by hydrogen peroxide, 100 microM, an NO donor (NOC-22, 400 microM), or the substrate for NO synthase (l-arginine, 5 mM). We conclude that net oxidant activity in resting muscle fibers is 1) decreased at subphysiological temperatures, 2) increased by CO(2) exposure, and 3) influenced by muscle-derived ROS and NO derivatives to similar degrees.
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Affiliation(s)
- Sandrine Arbogast
- Dept. of Physiology, Univ. of Kentucky, 800 Rose St., Rm. MS-509; Lexington, KY 40536-0298, USA
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