Endoscopy
Introduction
The Endoscopy Division covers
three fields of interest: the gastrointestinal (GI) tract, the respiratory
system, and the head and neck. A total of 7,952 endoscopic examinations were
performed in 1999, of which 6,979 were GI endoscopy, 709 broncho-scopy, and
264 laryngoscopy. Recently, we have noted a remarkable increase in the number
of endoscopic treatments, such as endoscopic mucosal resection (EMR), percutaneous
endoscopic gastro-stomy (PEG), endoscopic dilatation, and metallic stenting.
A high detection rate for esophageal carcinoma as a result of GI endoscopy
is a characteristic of our hospital and is explained by the fact that the
large number of patients with head and neck cancer who are at high risk for
also having esophageal cancers are examined at our division.
We have operated a digital
filing system for endoscopic images since 1997. The filing system makes it
easy to compare new images with older ones of the same patients. The digital
images have high-quality resolution and can be preserved long-term using the
EVIS 240 system. In addition, we have introduced a new digital filing system
that is connected to the local area network, allowing us to transmit the digital
images to other divisions easily. This system has also been convenient for
training new physicians.
Routine Activities
An electronic laryngoscope
is routinely used in the pretreatment and postoperative evaluations of head
and neck cancer patients. We also find it useful for patient education. Recent
developments of instruments and techniques include metallic stenting for malignant
esophageal stenosis, PEG for palliation, ultrathin cholangiopancreatoscopy,
and adaptive enhancement by image processing. An endoscopic ultrasonography
(EUS) provides important information in staging and determining resectability.
EUS-guided fine-needle aspiration or biopsy is being conducted in patients
with submucosal tumors or nodes adjacent to the GI tract wall.
Therapeutic frontiers are also
being explored with the use of EMR for the treatment of early mucosal cancers.
The percentage of cases treated with EMR has been increasing in early esophageal,
gastric, and colorectal cancers, and this increase is caused by the expansion
of our knowledge of indications. New techniques are available now that overcome
the earlier limitation in the size of tumors that could be detected and treated,
such as endoscopic resection using an insulating-tipped diathermic needle
knife for the treatment of early gastrointestinal cancer. We have used a magnifying
colonoscopy (CF200Z, Olympus Optical Co., Ltd., Japan) routinely since December
1993. Endoscopic polypectomy and EMR are now performed in 37% of all examinations.
We have performed lung biopsies
under real-time CT fluoroscopic guidance to diagnose early lung cancer in
a large number of cases, and this protocol has yielded promising results.
Brachytherapy is applied to relapsed cases of lung cancer with a high response
rate.
New Developments
The correct assessment of gastrointestinal
mucosal color is extremely important in the endoscopic diagnosis of digestive
tract diseases. A new diagnostic method using an endoscopic spectroscopy system
(ESS) has been developed for the examination of the spectral characteristics
of tissue in the GI tract. In our study, each lesion in the GI tract had its
own peculiar spectral characteristics, which suggested that ESS might become
a useful modality for clarifying the spectral characteristics of malignant
lesions in comparison with any other benign lesions.
Adaptive enhancement by image
processing is effective for the diagnosis of the crypt pattern of colonic
tumors, for determining the extent of cancerous invasion in early gastric
cancers, and for ulcer staging. We are also studying image analysis of the
fine mucosal network pattern by magnifying endoscopy. We believe these studies,
along with progress in electronic video endoscopy, are very promising in terms
of enhancing objective and quantitative endoscopic diagnoses.
Genetic and immunohistochemical
analyses using endoscopic biopsy specimens have allowed the prediction of
chemosensitivity and survival in patients with advanced esophageal and gastric
cancers. We have also adopted these methods to study the growth and development
of hyperplastic polyps and superficial type lesions of the colon and rectum.
In addition, we have investigated the correlation between bacterial infection
and upper GI carcino-genesis. We found that mutant ALDH2-2 allele is strongly
associated with multiple dyaplastic or cancerous changes in the upper aerodigestive
tract and that exhalation of high levels of acetaldehyde and normal oral microflora
might be a regional source of this carcinogenic compound during drinking.
|
Number
of Patients Examined in 1998-1999 |
||
|
1998 |
1999 |
|
|
Upper
gastrointestinal endoscopy |
4629 |
4596 |
|
(131) |
(125) |
|
|
Endoscopic
dilation |
133 |
125 |
|
Colonoscopy |
2441 |
2370 |
|
(711) |
(886) |
|
|
Endoscopic
ultrasonography |
216 |
176 |
|
ERCP
and cholangioscopy |
84 |
58 |
|
Bronchoscopy |
755 |
709 |
|
Laryngoscopy |
246 |
264 |
|
(
): Number of cases treated by endoscopic mucosal resection and polypectomy; ERCP:
endoscopic retrograde cholangiopancreatography. |
||
(T. SHINKAI, Y. SANO)
