title: Extraesophageal saline enhances endoscopic ultrasonography to differentiate esophagus and adjacent organs.
abstract: OBJECTIVE
  To distinguish between the esophagus and adjacent organs using extraesophageal saline injection (ESI) in a canine model.
  
  
  METHODS
  ESI was performed through the esophagus under the guidance of linear-array endoscopic ultrasonography (EUS). Approximately 15 mL of methylene blue saline (0.5%) was then injected through each of the extraesophageal puncture points using a 22 G needle. Radial EUS examinations were conducted before and after ESI. EUS images of the trachea, tracheal bifurcation, arcus aortae and thoracic aorta were recorded. Vital signs were monitored during the ESI procedure and EUS examination. The dogs were then sacrificed for exploratory thoracotomy.
  
  
  RESULTS
  No obvious fluctuation in vital signs or serious adverse events occurred during the ESI procedure. On EUS imaging, an apparent hypoechoic area outside the esophagus, which separated the esophagus and adjacent organs, was visualized. The adventitious of the esophagus and adjacent organs were easily distinguished. The findings of subsequent exploratory thoracotomy confirmed the EUS findings: obvious accumulation of a blue liquid in the extraesophageal tissues, as well as in the esophageal-thoracic aorta space, esophageal-arcus aortae space and esophageal-tracheal space.
  
  
  CONCLUSIONS
  The esophagus and adjacent organs were successfully separated by ESI, and extraesophageal saline acted as an effective ultrasonic contrast agent.
authors.affiliation: Jian-Jun Li, Hong-Bo Shan, Long-Jun He, Li-Ming Chen, Xin-Xin Huang, Guang-Yu Luo, Yin Li, Guo-Liang Xu, Department of Endoscopy, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Guangdong Esophageal Cancer Institute, Guangzhou 510060, Guangdong Province, China.
authors.forename: Jian-Jun
authors.initials: JJ
authors.lastname: Li
authors.affiliation: Jian-Jun Li, Hong-Bo Shan, Long-Jun He, Li-Ming Chen, Xin-Xin Huang, Guang-Yu Luo, Yin Li, Guo-Liang Xu, Department of Endoscopy, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Guangdong Esophageal Cancer Institute, Guangzhou 510060, Guangdong Province, China.
authors.forename: Hong-Bo
authors.initials: HB
authors.lastname: Shan
authors.affiliation: Jian-Jun Li, Hong-Bo Shan, Long-Jun He, Li-Ming Chen, Xin-Xin Huang, Guang-Yu Luo, Yin Li, Guo-Liang Xu, Department of Endoscopy, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Guangdong Esophageal Cancer Institute, Guangzhou 510060, Guangdong Province, China.
authors.forename: Long-Jun
authors.initials: LJ
authors.lastname: He
authors.affiliation: Jian-Jun Li, Hong-Bo Shan, Long-Jun He, Li-Ming Chen, Xin-Xin Huang, Guang-Yu Luo, Yin Li, Guo-Liang Xu, Department of Endoscopy, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Guangdong Esophageal Cancer Institute, Guangzhou 510060, Guangdong Province, China.
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Wang
authors.affiliation: Jian-Jun Li, Hong-Bo Shan, Long-Jun He, Li-Ming Chen, Xin-Xin Huang, Guang-Yu Luo, Yin Li, Guo-Liang Xu, Department of Endoscopy, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Guangdong Esophageal Cancer Institute, Guangzhou 510060, Guangdong Province, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Xiong
authors.affiliation: Jian-Jun Li, Hong-Bo Shan, Long-Jun He, Li-Ming Chen, Xin-Xin Huang, Guang-Yu Luo, Yin Li, Guo-Liang Xu, Department of Endoscopy, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Guangdong Esophageal Cancer Institute, Guangzhou 510060, Guangdong Province, China.
authors.forename: Li-Ming
authors.initials: LM
authors.lastname: Chen
authors.affiliation: Jian-Jun Li, Hong-Bo Shan, Long-Jun He, Li-Ming Chen, Xin-Xin Huang, Guang-Yu Luo, Yin Li, Guo-Liang Xu, Department of Endoscopy, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Guangdong Esophageal Cancer Institute, Guangzhou 510060, Guangdong Province, China.
authors.forename: Xiao-Hai
authors.initials: XH
authors.lastname: Li
authors.affiliation: Jian-Jun Li, Hong-Bo Shan, Long-Jun He, Li-Ming Chen, Xin-Xin Huang, Guang-Yu Luo, Yin Li, Guo-Liang Xu, Department of Endoscopy, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Guangdong Esophageal Cancer Institute, Guangzhou 510060, Guangdong Province, China.
authors.forename: Xin-Xin
authors.initials: XX
authors.lastname: Huang
authors.affiliation: Jian-Jun Li, Hong-Bo Shan, Long-Jun He, Li-Ming Chen, Xin-Xin Huang, Guang-Yu Luo, Yin Li, Guo-Liang Xu, Department of Endoscopy, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Guangdong Esophageal Cancer Institute, Guangzhou 510060, Guangdong Province, China.
authors.forename: Guang-Yu
authors.initials: GY
authors.lastname: Luo
authors.affiliation: Jian-Jun Li, Hong-Bo Shan, Long-Jun He, Li-Ming Chen, Xin-Xin Huang, Guang-Yu Luo, Yin Li, Guo-Liang Xu, Department of Endoscopy, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Guangdong Esophageal Cancer Institute, Guangzhou 510060, Guangdong Province, China.
authors.forename: Yin
authors.initials: Y
authors.lastname: Li
authors.affiliation: Jian-Jun Li, Hong-Bo Shan, Long-Jun He, Li-Ming Chen, Xin-Xin Huang, Guang-Yu Luo, Yin Li, Guo-Liang Xu, Department of Endoscopy, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Guangdong Esophageal Cancer Institute, Guangzhou 510060, Guangdong Province, China.
authors.forename: Guo-Liang
authors.initials: GL
authors.lastname: Xu
mesh_terms: D059925:Anatomic Landmarks; D000818:Animals; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging; D004396:Coloring Agents; D003287:Contrast Media / Q000008:administration & dosage; D004285:Dogs; D019160:Endosonography; D004947:Esophagus / Q000000981:diagnostic imaging*; D007267:Injections; D008297:Male; D008751:Methylene Blue; D023421:Models, Animal; D011237:Predictive Value of Tests; D011677:Punctures; D012965:Sodium Chloride / Q000008:administration & dosage; D013908:Thoracotomy; D014132:Trachea / Q000000981:diagnostic imaging; D018615:Ultrasonography, Doppler, Color
chemical_list: D004396:Coloring Agents; D003287:Contrast Media; D012965:Sodium Chloride; D008751:Methylene Blue
keywords: Aorta; Endoscopic ultrasonography; Esophageal cancer; Extraesophageal saline injection; Staging; Trachea