Endoscopy Division
Introduction
The Endoscopy Division comprises of gastro-intestinal, respiratory, and
otolaryngology teams. Thegastrointestinal team has 6 staff physicians,
1 chief resident, 7 residents, and several rotating residents, the respiratory
team has 3 staff physicians and several trainees, and the otolaryngology
team has 1 staff physician.
Dramatic developments have occurred in the operational mechanism and design
of endoscopes and the accessory apparatus recently, and clinical applications
using this equipment are evolving. In the gastrointestinal division, endoscopic
treatments such as endoscopic mucosal resection (EMR), percu-taneous endoscopic
gastrostomy (PEG), and stent placement are increasingly applied. In the
field of bronchoscopy, bronchoscopic treatments are coupled with computerized
tomography (CT) for the treatment of airway stenosis, minute peripheral
lung cancer, and the like.
Educational activities are an important part of our divisionis activities.
Many students, residents, and national and foreign post-graduate doctors
attend our training course.
Routine Activities@
All diagnostic knowledge and techniques including magnifying endoscopy
and endoscopic ultrasonography are provided in order to detect and evaluate
small early malignant lesions. With increase in the number of gastrointestinal
mucosal cancer patients, endoscopic mucosal resection (EMR) is performed
more frequently. In 2001 we performed 585 EMRs (esophagus 58, stomach
319, colon 208). In gastric cancer treatment, 96% (305/318) of EMR were
performed using an insulating-tipped (IT) diathermic knife and the proportion
of EMR cases to all treated early gastric cancer cases reached about 45%.
However, even with the success of EMR in resecting early gastric cancer,
a close follow-up program should be instituted, because the controllability
of micrometastases after EMR is uncertain. Concerning major complications
such as perforation or active bleeding during EMR using the IT knife,
all 12 cases (4%) were treated with endoscopic clippings, argon plasma
coagulation (APC) or hot biopsy method. Regarding the palliative treatment
for patients with terminal disease, placement of self-expandable metallic
stent for malignant obstruction was performed in 9 cases, and PEG for
malignant dysphagia in 17 cases.
For respiratory diseases, we have focused on diagnosis of minute peripheral
malignancies detected by CT, which leads to earlier surgical treatments,
and less invasive treatments including bronchoscopic therapies. This is
possible with the use of the multi-purpose bronchoscopy system consisting
of bi-plane fluoroscopes and spiral CT with CT-fluoroscopy. Endobronchial
malignancies are diagnosed by videobronchoscopes, an endobronchial ultrasound
system, and high-resolution CT, and are treated by Nd-YAG laser vaporization,
photodynamic therapy, brachytherapy, and tracheobronchial prosthesis.
In addition, image diagnosis including that with high resolution CT is
also a routine activity for broncho-scopy, which leads to more accurate
and safer diagnosis, and earlier detection of tracheobronchial malignancies.The
gastrointestinal team and respiratory team hold the film reading conferences
on Monday and Tuesday evenings and Wednesday morning, respectively. Furthermore,
we attend all clinical conferences in each division as endoscopists.
Research Activities
For the improvement of en bloc resectability of large lesions, we developed
an improved technique named "PTA-EMR", percutaneus traction-assisted
EMR. We apply trtraction clips attached to the edge of lesion by a thin
retractor inserted percutaneously through the abdominal wall, and then
resect the lesion by IT-knife. It provides counter traction to the lesion
for easier mucosectomy and can be carried out without systemic anesthesia.
A close association between Helicobacter pylori (H. pylori) infection
and gastric malignancies has been reported. Although the data on long-term
outcome are lacking, the cure rate of low-grade MALT (mucosaassociation
lymphoid tissue) lymphoma after H. pylori eradication was 76% (48/63)
and the atrophy-like discolored mucosa was indicated as an endoscopic
finding to heighten the accuracy of prognosis. Some molecular markers
for prognosis evaluation is also under active examination. On the other
hand, to elucidate the causal link between H. pylori infection and gastric
carcino-genesis in human being, the reversibility of gastric dysplasia,
considered as a premalignant condition after, H. pylori eradication was
examined. 7 out of 28 lesions (25%) disappeared endoscopically and histologically.
Despite the endoscopic regression, however, there are some lesions without
histological change. We should take caution in the endoscopic diagnosis
for faint gastric
mucosal abnormalites in the H. pylori eradicated patients.
Our efforts have been focusing on new diagnostic and therapeutic strategies
including bronchoscopy , which are provided by CT-screening for lung cancer
and lead to cure and less invasive treatments of lung cancer.In addition
to this, photodynamic therapy for airway stenosis, endoscopes with brand-new
concepts, and new guiding systems applied to catheter examination as well
as endoscopy are being researched.
New Developments
The Japanese Intervention Trial of H. pylori (JITHP) to clarify the reversibility
of gastric pre-cancerous conditions by H. pylori eradication is ongoing.
751 patients were enrolled and will be followed-up until March 2004. However,
in some countries, the incidences of gastric cancer is less well associated
with the infection rates,this suggests that genetic and/or environmental
factors are also important factors in the pathogenesis of this disease.
A comparative study of atrophic gastritis in Japan and United Kingdom
is ongoing.
Two randomized controlled trials (RCT) concerning colorectal cancer are
planned. One is to evaluate the inhibitory effect of lactoferin on colorectal
carcinogenesis, and this will start in February 2002. Another trialis
to establish a reasonable surveillance program by total colonoscopy. Retrospective
cohort study by 6 institutions revealed that screening colonoscopy should
be performed at least three-yearly for patients without polyp or with
polyps less than 5 mm and yearly for patients with large polyp (larger
than 6 mm) or intramucosal cancer without complete removal of minute polyps
(5< mm). This RCT will start in October 2002.
D. SAITO
Number of Endoscopic Examinations in 2001
|
GIE
|
FBS
|
LS
|
ERCP
|
Total
|
|||
|
Esophagus
|
Stomach
|
Colon
|
|||||
| No. of examinations |
9,694
|
3,693
|
500(16)
|
94
|
3
|
13,984
|
|
| EUS |
210
|
168
|
126
|
504
|
|||
| Polypectomy* |
8
|
918
|
926
|
||||
| EMR* |
58
|
319
|
208
|
585
|
|||
| Laser |
4
|
44
|
|||||
| PEG |
17
|
17
|
|||||
| Stent |
9
|
13
|
22
|
||||
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