Ines E Tinhofer1, Chin-Yu Yang2, Courtney Chen3, Ming-Huei Cheng1,2. 1. Division of Reconstructive Microsurgery, Department of Plastic and Reconstructive Surgery, Chang Gung Memorial Hospital, Chang Gung University and Medical College, Taoyuan, Taiwan. 2. Center for Tissue Engineering, Chang Gung Memorial Hospital, Taoyuan, Taiwan. 3. Medical student, UC San Diego School of Medicine, San Diego, California.
Abstract
BACKGROUND: Reported ischemia time of vascularized lymph nodes was 5 hours. This study investigated the effects of arterial ischemia and venous occlusion on vascularized lymph node function in rats. METHODS: Bilateral pedicled groin lymph node flaps were raised in 27 Lewis rats. Femoral artery and vein were separated and clamped for 1, 3, 4, or 5 hour(s). Lymph node flap perfusion and drainage were assessed by laser Doppler flowmetry and indocyanine green lymphography. Histologic changes were assessed using hematoxylin and eosin stain, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL), and glutathione assays. RESULTS: Perfusion units of 2.84 ± 1.41, 2.46 ± 0.64, 2.42 ± 0.37, and 2.01 ± 0.90 were measured in arterial ischemia groups, and 1.71 ± 0.45, 2.20 ± 0.98, 1.49 ± 0.35, and 0.81 ± 0.20 in venous occlusion groups after 1, 3, 4, and 5 hours of clamping, respectively. Lymphatic drainage showed mean latency periods of 5.33 ± 0.88, 9.00 ± 3.21, 10.00 ± 2.08, and 24.50 ± 11.50 seconds in arterial clamping groups, and 25.00 ± 3.61, 26.00 ± 3.06, 23.33 ± 4.41, and 152.00 ± 0 seconds in venous clamping groups, respectively. Severe medullary and cortical congestion and hemorrhage on histology and cell damage by glutathione levels and TUNEL assay were found after 4 hours of venous clamping. CONCLUSIONS: Arterial ischemia and venous occlusion impact the function and viability of vascularized lymph node flaps differently. The critical venous occlusion time was 4 hours.
BACKGROUND: Reported ischemia time of vascularized lymph nodes was 5 hours. This study investigated the effects of arterial ischemia and venous occlusion on vascularized lymph node function in rats. METHODS: Bilateral pedicled groin lymph node flaps were raised in 27 Lewis rats. Femoral artery and vein were separated and clamped for 1, 3, 4, or 5 hour(s). Lymph node flap perfusion and drainage were assessed by laser Doppler flowmetry and indocyanine green lymphography. Histologic changes were assessed using hematoxylin and eosin stain, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL), and glutathione assays. RESULTS: Perfusion units of 2.84 ± 1.41, 2.46 ± 0.64, 2.42 ± 0.37, and 2.01 ± 0.90 were measured in arterial ischemia groups, and 1.71 ± 0.45, 2.20 ± 0.98, 1.49 ± 0.35, and 0.81 ± 0.20 in venous occlusion groups after 1, 3, 4, and 5 hours of clamping, respectively. Lymphatic drainage showed mean latency periods of 5.33 ± 0.88, 9.00 ± 3.21, 10.00 ± 2.08, and 24.50 ± 11.50 seconds in arterial clamping groups, and 25.00 ± 3.61, 26.00 ± 3.06, 23.33 ± 4.41, and 152.00 ± 0 seconds in venous clamping groups, respectively. Severe medullary and cortical congestion and hemorrhage on histology and cell damage by glutathione levels and TUNEL assay were found after 4 hours of venous clamping. CONCLUSIONS:Arterial ischemia and venous occlusion impact the function and viability of vascularized lymph node flaps differently. The critical venous occlusion time was 4 hours.
Authors: David P Perrault; Gene K Lee; Antoun Bouz; Cynthia Sung; Roy Yu; Austin J Pourmoussa; Sun Young Park; Gene H Kim; Wan Jiao; Ketan M Patel; Young-Kwon Hong; Alex K Wong Journal: PLoS One Date: 2020-01-10 Impact factor: 3.240
Authors: Abdullah S Eldaly; Francisco R Avila; Ricardo A Torres-Guzman; Karla C Maita; John P Garcia; Luiza P Serrano; Humza Y Saleem; Antonio J Forte Journal: J Clin Transl Res Date: 2022-05-25