Research Report
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World J Gastroenterol. Sep 21, 2014; 20(35): 12551-12558
Published online Sep 21, 2014. doi: 10.3748/wjg.v20.i35.12551
Extraesophageal saline enhances endoscopic ultrasonography to differentiate esophagus and adjacent organs
Jian-Jun Li, Hong-Bo Shan, Long-Jun He, Thomas D Wang, Huan Xiong, Li-Ming Chen, Xiao-Hai Li, Xin-Xin Huang, Guang-Yu Luo, Yin Li, Guo-Liang Xu
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
Thomas D Wang, Division of Gastroenterology, University of Michigan, Ann Arbor, MI 48109, United States
Huan Xiong, Department of Medical Record Statistics, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, Guangdong Province, China
Xiao-Hai Li, Department of Cardiothoracic Surgery, The First Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine, Guangzhou 5100405, Guangdong Province, China
Author contributions: Li JJ, Shan HB and He LJ contributed equally to this work; Li JJ designed this study and was responsible for this work; Shan HB, He LJ were clinical investigators; Xiong H, Chen LM, Luo GY and Li Y collected and analyzed data; Li XH and Huang XX performed thoracic anatomy and obtained the samples; Wang TD and Xu GL served as scientific advisors; Li JJ wrote and revised the manuscript; all authors approved the final version to be published.
Supported by Science and Technology Plan Projects of Guangdong Province, China No. 2011B080701015 and No. 2012B061700076
Correspondence to: Guo-Liang Xu, MD, Professor, Department of Endoscopy, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Guangdong Esophageal Cancer Institute, Dongfeng East Road 657, Guangzhou 510060, Guangdong Province, China. xugl@sysucc.org.cn
Telephone: +86-20-87343106 Fax: +86-20-8734224
Received: March 3, 2014
Revised: April 29, 2014
Accepted: June 12, 2014
Published online: September 21, 2014
Processing time: 199 Days and 19.5 Hours
Abstract

AIM: 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.

CONCLUSION: The esophagus and adjacent organs were successfully separated by ESI, and extraesophageal saline acted as an effective ultrasonic contrast agent.

Keywords: Esophageal cancer; Endoscopic ultrasonography; Extraesophageal saline injection; Aorta; Trachea; Staging

Core tip: The esophagus and adjacent organs were distinguished by extraesophageal saline injection (ESI) in dogs to identify better the esophageal adventitia and adjacent organs by endoscopic ultrasonography (EUS). EUS showed that the esophagus and adjacent organs were separated clearly in the extraesophageal liquid dark area. The findings provide an adequate basis for combined ESI and EUS for accurate preoperative identification of Stage T3 and T4 esophageal cancer.