Study on Transtracheobronchial Ultrasonography in Diagnosing Tracheobronchial Invasion of Esophageal Cancer

Yoshihiko Nishimura, Harushi Osugi, Kiyotoshi Inoue, Nobuyasu Takada, Takanobu Funai, Toshihiko Kato, Shigeru Lee, Sinichi Taguchi, Miyuki Fujita and Hiroaki Kinoshita

Second Department of Surgery, Osaka City University, Medical School

Preoperative evaluation of cancer invasion into the trachea and bronchus is of vital importance in patients with cancer in the upper thoracic esophagus. The usefulness of transtracheobronchial ulorasonography (TBUS) in diagnosing cancer invasion into the tracheobronchus was studied. Preliminary ultrasonic observations of tracheal specimens revealed that the normal tracheal wall can be delineated as a structure composed of 5 layers. A total of 19 patients with esophageal cancer suspected to invade to the trachea and/or bronchus by CT were examined. Informed consent was obtained from all patients. A 20-MHz sonoprobe (UM-3R, Olympus Optical Co. Ltd.), which was passed through the biopsy channel of a fibroptic bronchoscope (ST-30, Olympus Optical Co. Ltd.) was used. The balloon on the sonoprobe was inflated with water to attach to the tracheobronchial mucosa in order to obtain an echo window. The tracheobronchial wall was delineated as 5 layers. The esophageal lesion was detected as a low echoic area. The presence of tracheobronchial invasion was diagnosed by interruption in the most external high echoic layer of the tracheobronchus. Tracheobronchial invasion was not found surgically in the 6 patients diagnosed as having no invasion. In the 13 patients with the interruption, bronchial invasion was confirmed at operation in all of the 9 patients who had thoracotomy. There were no complications caused by TBUS. TBUS was useful in evaluating cancer invasion into the tracheobronchus because it is effective and safe, and is more accurate than CT for visualizing the layered structure of the tracheobronchus.

Key words
transtracheobronchial ultrasonography, esophageal cancer, bronchial invasion, preoperative evaluation

Reprint requests
Yoshihiko Nishimura Second Department of Surgery, Osaka City University, Medical School 1-5-7 Asahi-machi, Abeno-ku, Osaka, 545-8561 JAPAN

Accepted
June 22, 1999

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