食道外科における最先端診断・手術手技開発とCAL

Introduction :
Precise diagnosis of tracheobronchial invasion of advanced esophageal cancer is essential to select an appropriate treatment and to improve the prognosis, but it is difficult to make a precise diagnosis with conventional modalities. Esophageal cancer surgery is invasive with high mortality and morbidities rates. Therefore, less invasive and adequate treatment under the accurate diagnosis have been pursuing. Development of state of the arts in those area is very important but difficult to make with animals. Recent advances of cadaveric study realized them. Tokushima University Hospital Clinical Anatomy Lab（CAL）started cadaveric study since November２０１６.
Methods :
We examined the usefulness of convex-proved endobronchial ultrasound （CP-EBUS） to diagnose tracheobronchial invasion of esophageal cancer.
Agarose gel was injected into the esophageal muscle layer to create the tumor model. The tracheal adventitia was cauterized with an electric scalpel to create the tracheal invasion model. The ultrasonic changes observed with CP-EBUS was compared with histopathologic findings.
We also trained and developed mediastinoscopic esophagectomy using a cadaveric study.
Results :
Cadaveric study confirmed that the third layer observed with CP-EBUS corresponded with the tracheal adventitia. And esophageal tumor was recognized well, the tracheal invasion model showed disappearance of the third layer and an interruption of the adventitia with CP-EBUS. They were confirmed with histopathology.
We could perform the mediastinoscopic esophagectomy in cadaver, retrieving the procedure same as real operation, with preserving the left recurrent laryngeal nerve, the trachea, the aorta, and etc.
Conclusion :
We examined the utility of diagnostic strategy of the tracheobronchial invasion of the esophageal cancer and developed the mediastinoscopic surgery using cadaver. There are many benefits in the cadaveric study and we will develop it for new strategy of diagnosis and treatment.