title: Lymphatic Territories (Lymphosomes) in Swine: An Animal Model for Future Lymphatic Research.
abstract: BACKGROUND
  The swine is a common preclinical large-animal model for medical research because of the resemblance of its tissue structures to those of humans. However, the lymphatic system in swine is poorly understood. The authors investigated the lymphatic system and defined territories (lymphosomes) in swine using the microinjection technique.
  
  
  METHODS
  Six swine (two male and four female 17.5- to 50-kg Sus domesticus) were used. Real-time indocyanine green fluorescence lymphography was performed in four live swine. After the animals were killed, the authors injected a radiocontrast mixture consisting of barium sulfate and hydrogen peroxide with red acrylic dye directly into lymphatic vessels in six swine carcasses. Courses of the lymphatic vessel were analyzed radiographically. The lymphatic vessels were dissected meticulously and chased until they connected to the first-tier (sentinel) lymph node. This procedure was repeated throughout the body until all the relationships between the lymphatic vessels and lymph nodes were defined.
  
  
  RESULTS
  The authors successfully mapped the superficial lymphatic vessels and their corresponding lymph nodes. Indocyanine green fluorescence lymphography and subsequent radiography revealed that the swine lymphatic system contained seven lymphosomes: parotid, mandibular, dorsal cervical, ventral cervical, subiliac, inguinal, and popliteal territories. Of note, no lymph nodes existed in the superficial axillary region.
  
  
  CONCLUSIONS
  The swine could be a useful large-animal model for lymphatic research because of the anatomical consistency of the lymphosomes among animals and the sizable lymphatic vessels. However, swine lack the superficial axillary lymph node found in humans, suggesting that swine may not be a good model for breast cancer-related lymphedema.
authors.affiliation: Houston, Texas From the Department of Plastic Surgery, The University of Texas M. D. Anderson Cancer Center.
authors.forename: Ran
authors.initials: R
authors.lastname: Ito
authors.forename: Hiroo
authors.initials: H
authors.lastname: Suami
mesh_terms: D000818:Animals; D035843:Biomedical Research / Q000639:trends; D005260:Female; D005544:Forecasting; D007208:Indocyanine Green; D008198:Lymph Nodes / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D042601:Lymphatic Vessels / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D008220:Lymphography / Q000379:methods; D008297:Male; D023421:Models, Animal; D034421:Sus scrofa; D013552:Swine
chemical_list: D007208:Indocyanine Green