Endoscopy

Introduction
The Endoscopy Division now covers three fields of interest: the gastrointestinal (GI) tract, respiratory system and head and neck. A total of 8056 endoscopic examinations were performed in 1997, including 7058 GI endoscopic, 756 bronchoscopic, and 252 laryngoscopic examinations. Recently, a remarkable increase has been noted in the number of endoscopic treatments, such as endoscopic mucosal resection (EMR), endoscopic dilatation and stenting. Endoscopic ultrasonography for deciding of treatment methods has also increased. The high rate of esophageal carcinoma detection with GI endoscopy is one of the hallmarks of our hospital. This is explained by the large number of head and neck cancer patients examined.
Optical fiberscopes have been entirely replaced by electronic endoscopes. The endoscopy units and their environment are now being computerized with the aim of constructing an integrated system for storage, management and transmission of digital images.

Routine Activities
The routine use of a magnifying endoscope in colonoscopy is superior for the recognition of colorectal tumor crypt patterns, particularly in early colorectal cancer. An electronic laryngoscope is routinely used in pretreatment and postoperative evaluations of head and neck cancer patients. We also find it useful for patient education. Examples of recent diagnostic instruments and techniques include endoscopic ultrasonography and the miniature probe, ultrathin cholangiopancreatoscopy, metallic stenting for malignant esophageal stenosis, and a real time adaptive structure-enhancement system with a microprocessor.
Therapeutic frontiers are also being explored in the use of EMR for early mucosal cancers. The percentage of cases treated by EMR has been increasing for early esophageal, gastric and colorectal cancers. This rate is increasing annually due to advances in the diagnosis and the expansion of indications. In colonoscopy, endoscopic polypectomy and EMR are now performed in 34% of all examinations.
For the diagnosis of early lung cancer, lung biopsy under real-time CT fluoroscopic guidance has been performed in a large number of cases, and has yielded promising results. Brachytherapy is applied to relapsed cases of lung cancer and a high response rate has been achieved.

New Developments
One of our newest developments, the endoscopic spectroscopy system (ESS), can reveal the spectroscopic color value of a randomly sampled area by employing a computer program. We believe that ESS will become a useful modality for obtaining spectral data in tissues of the GI tract and for clarifying the spectral characteristics of malignancies in comparison with benign lesions. Light induced autofluorescence endoscopy (LIFE) has recently been developed as a sensitive screening tool for neoplastic lesions of the GI tract. Percutaneous transhepatic cholangioscopy using the LIFE system has been performed for patients with biliary malignancy. Specific fluorescence from cancerous lesions can be differentiated from the fluorescence of normal tissue. This method is, therefore, expected to be very useful for preoperative diagnosis of cancer extension. The detectability of colorectal polyps by three-dimensional CT colonography is now being studied in comparison with that achieved colonoscopically. Genetic and immunohistochemical analyses using biopsy specimens have allowed the prediction of chemoresponsiveness and patient survival in advanced esophageal and gastric cancers. We have adapted these methods to study the growth and development of colorectal tumors.

Statistics
Number of Patients Examined in 1996-1997

19961997
Upper gastrointestinal endoscopy3795 (80)4265 (111)
Endoscopic dilation112 133
Colonoscopy2112 (703)2316 (780)
Endoscopic ultrasonography186263
ERCP and cholangioscopy11081
Bronchoscopy662756
Laryngoscopy241252
( ): number of cases treated by endoscopic mucosal resection and polypectomy.

(H. Tajiri)

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