Diseases of the Esophagus (2011) 24, 92–98
DOI: 10.1111/j.1442-2050.2010.01098.x
Original article
dote_1098
92..98
Unsedated transnasal ultrathin esophagogastroduodenoscopy may provide
betterdiagnostic performance in gastroesophageal reflux disease
A. Mori,1 N. Ohashi,1 A. Yoshida,1 M. Nozaki,1 H. Tatebe,2 M. Okuno,2 Y. Hoshihara,3 M. Hongo4
Department of Gastroenterology, Ichinomiya Nishi Hospital, Aichi, and 2Department of Internal Medicine,
Inuyama Chuo Hospital, Aichi, Japan, and 3Clinic of the Ministry of Economy, Trade and Industry, Tokyo,
Japan, and 4Department of Comprehensive Medicine, Tohoku University Hospital, Sendai, Japan
1
SUMMARY. Transnasal ultrathin esophagogastroduodenoscopy (N-EGD) with less gagging reflexes under nonsedation is likely suitable for the diagnosis of gastroesophageal reflux disease (GERD), however, N-EGD might
have drawbacks, including its low image resolution. Limited information is available regarding the diagnosability
of N-EGD for GERD. We compared the utility and gagging reflexes of three different endoscopies, including
N-EGD, ultrathin transoral EGD (UTO-EGD) and conventional oral EGD (CO-EGD), in the diagnosis of
GERD. We performed screening endoscopy in 1580 patients (N-EGD n = 727, UTO-EGD n = 599, CO-EGD
n = 254) and compared the frequency distributions of the severity of reflux esophagitis, hiatus hernia, and Barrett’s
epithelium to estimate the diagnostic performance of each endoscopy. We also analyzed patients’ tolerability of
endoscopy by the subjective evaluation of gagging reflexes. In the diagnosis of reflux esophagitis and Barrett’s
epithelium, there was no significant difference in the frequency distributions of the severity of the diseases among
three EGDs. However, the incidence of Barrett’s epithelium was higher than that in the previous nationwide survey
of GERD in Japan. The evaluated size of hiatus hernia was smaller in N-EGD than in two other peroral
endoscopies. The size of hiatus hernia correlated significantly with severity of gagging reflexes that was also lowest
when diagnosed with N-EGD. N-EGD had an equivalent performance in the diagnosis of reflux esophagitis and
Barrett’s epithelium compared with CO-EGD. Enlargement of hiatus hernia induced by gagging reflexes was
minimal in N-EGD, resulting in its better performance in the diagnosis of Barrett’s epithelium.
KEY WORDS: Barrett’s epithelium, gastroesophageal reflux disease (GERD), hiatus hernia, reflux esophagitis,
transnasal esophagogastroduodenoscopy (EGD).
INTRODUCTION
The frequency of gastroesophageal reflux disease
(GERD) has recently been increasing in Japan.1
GERD is known to induce not only poor quality of
life resulting from its symptoms but also reflux esophagitis (RE) as a complication.2 RE has been reported
to cause Barrett’s esophagus that is associated with
the onset of the esophageal adenocarcinoma.3 For
such reasons, GERD has come to be regarded as an
important disease also in Japan as well as in Western
countries.
Endoscopic surveillance is essential for the diagnosis of GERD-associated diseases, including RE,
Correspondence to: Dr Akihiro Mori, MD, Department of
Gastroenterology, Ichinomiya Nishi Hospital, 494-0001
Ichinomiya Aichi, Japan, E-mail: [email protected]
92
sliding esophageal hiatus hernia (HH), and Barrett’s
epithelium (BE). However, difficulties are sometimes
encountered in the observation of the esophagus
when conventional peroral esophagogastroduodenoscopy (CO-EGD) is performed because CO-EGD
induces gagging reflexes under the non-sedative conditions. Moreover, when CO-EGD is performed
under sedation, breathing control becomes impossible, which may be also disadvantageous for the
diagnosis of GERD-associated diseases. On the other
hand, the breath control is easy in transnasal
ultrathin EGD (N-EGD) with less gagging reflexes
under non-sedation, and thus the procedure is likely
suitable for the endoscopic surveillance of the
esophagogastric junction (EGJ). However, concerns
have been reported regarding N-EGD because of its
drawbacks such as low image resolution and low
luminous intensity.4–6
© 2010 Copyright the Authors
Journal compilation © 2010, Wiley Periodicals, Inc. and the International Society for Diseases of the Esophagus
Diagnosability of transnasal EGD in GERD 93
Therefore, it seems worthwhile to examine if
N-EGD is beneficial in the diagnosis of GERDassociated diseases when compared with oral EGD.
However, limited information is available regarding
the diagnostic utility of N-EGD for GERD. In the
present study, we have compared three different
endoscopic procedures, including N-EGD, ultrathin
transoral EGD (UTO-EGD) and CO-EGD, to estimate their diagnosability for GERD-associated diseases. Particularly, attention has been paid if the
technical characteristics of N-EGD such as its low
image resolution and less gagging reflexes may affect
the diagnostic capability.
PATIENTS AND METHODS
anesthesia was achieved using lidocaine jelly
(approximately 5 mL) before either UTO-EGD or
CO-EGD.
Observation of EGJ
Endoscopic observations of the lower esophagus
were performed according to the following procedures: (i) we observed the lower esophagus at the time
of initial insertion into EGJ (before inserting into the
stomach) to reduce the air in the stomach; (ii) we
asked the patients to hold their breath after deep
inspiration; and (iii) we observed the EGJ at the time
when the junction opened most widely in case peristalsis developed. A definitive diagnosis was made
using endoscopic photography by three senior endoscopists with more than 10 years of experience.
Study design and patients
We have conducted a prospective observational
study. One thousand five hundred and eighty consecutive outpatients who underwent EGD for screening upper intestinal tract disorders in Inuyama Chuo
Hospital and Ichinomiya Nishi Hospital between
January 2007 and March 2008, were enrolled in the
present study. We excluded patients with esophagogastric cancers, gastroduodenal ulcers, and histories
of esophagogastrointestinal surgery as well as those
taking proton-pomp-inhibitors or histamine-2 receptor antagonists. All patients gave written informed
consent before participating in the study. The study
was performed in compliance with the Declaration of
Helsinki and was approved by the review board for
human research in the respective hospital. All
patients were informed that it was uncertain which
endoscopy was more comfortable and that ultrathin
endoscopy might have lower image resolution.
Patients were asked to select one of three options;
N-EGD, UTO-EGD, or CO-EGD, according to
their free will.
Endoscope procedure
Endoscopy was performed by senior endoscopists
with more than 5 years of experience. Two types of
endoscopes were used; an ultrathin endoscope
(EG530N, Fujinon-Toshiba, Tokyo, Japan) with a
tip diameter of 5.9 mm for both transnasal and oral
approaches and a conventional endoscope (GIF
XQ240 or XQ 260; Olympus, Tokyo, Japan) with a
tip diameter of 9.0 mm for oral approach. Only
topical anesthesia was used, without any sedative or
anti-cholinergic agents. The nasal cavity was prepared before N-EGD by spraying three doses of
0.111% tramazoline hydrochloride (Alfresa Pharma,
Osaka, Japan), followed by the insertion of an 18 Fr
catheter covered with 8% lidocaine liquid (Astra
Zeneca, Tokyo, Japan) for 3 minutes.7 Pharyngeal
Diagnosis of RE
The endoscopic assessment of RE was performed
according to the modified Los Angeles (LA) classification8 consisting of LA grade N (no minimal change
and no mucosal break), LA grade M (minimal change
without mucosal break), and LA grades A-D (Fig. 1).
Diagnosis of HH
The endoscopic assessment of HH was performed
according to the modified Makuuchi classification9
consisting of HH grade 0 (no HH), HH grade 1
(partially HH), HH grade 2 (complete HH <3 cm),
and HH grade 3 (complete HH > = 3 cm), measured
by the scale on the endoscopic shaft (Fig. 2).
Diagnosis of BE
We defined EGJ as the distal end of the lower esophageal palisade vessels and defined BE as the mucosa
between EGJ and squamocolumnar junction. We
measured both of the shortest and longest width of
BE with the scale on the endoscopic shaft and classified BE into 4 grades; BE grade 0 (no BE), BE grade
1 (circumferential (C) or tongue (T) type, longest
BE < 1 cm), BE grade 2 (C type, 3 cm > longest
BE ⱖ 1 cm or T type, longest BE ⱖ 1 cm), and grade
3 (C type, shortest BE ⱖ 3 cm) (Fig. 3).
Evaluation for gagging reflex
The gagging score was determined by a 10-point
visual analog scale from 0 (no gagging) to 10 (unbearable). While taking a rest in the recovery room after
completion of the endoscopy, patients were asked by
independent qualified personnel regarding the presence of gagging reflex during procedure by which they
were examined.
© 2010 Copyright the Authors
Journal compilation © 2010, Wiley Periodicals, Inc. and the International Society for Diseases of the Esophagus
94 Diseases of the Esophagus
Fig. 1 Grading classification of reflux esophagitis according to the modified Los Angeles classification (LA grade). The grades consist
of LA grade N (no minimal change and no mucosal break), LA grade M (minimal change without mucosal break) and LA grades
A–D.
Statistical analysis
Statistical analysis was carried out using the chisquared test, Mann–Whitney test, Kruskal–Wallis
test, or Spearman’s rank correlation coefficient for
significant difference among non-parametric data
groups and using the one-factor analysis of variance
among more than three parametric data groups. In
Fig. 2 Grading classification of hiatus hernia according to the
modified Makuuchi classification (HH grade). The grades consist
of HH grade 0 (no HH), HH grade 1 (partially HH), HH grade
2 (complete HH < 3 cm) and HH grade 3 (complete
HH > = 3 cm), measured by the scale on the endoscopic shaft.
addition, in cases there was significant difference with
Kruskal–Wallis test among three groups, we evaluated significant difference between each two groups,
using the Mann–Whitney test. All analyses were
Fig. 3 Grading classification of Barrett’s epithelium (BE grade).
We defined EGJ as the distal end of the lower esophageal
palisade vessels and defined Barrett’s epithelium as the mucosa
between esophagogastric junction and squamocolumnar
junction. We measured both of the shortest and longest width of
BE with the scale on the endoscopic shaft and classified BE into
four grades: BE grade 0 (no BE); BE grade 1 (circumferential [C]
or tongue [T] type, longest BE < 1 cm); BE grade 2 (C type,
3 cm > longest BE > = 1 cm or T type, longest BE > = 1 cm); and
grade 3 (C type, shortest BE > = 3 cm).
© 2010 Copyright the Authors
Journal compilation © 2010, Wiley Periodicals, Inc. and the International Society for Diseases of the Esophagus
Diagnosability of transnasal EGD in GERD 95
Table 1 Patients characteristics and gagging score in three endoscopy groups
Patients (n)
Gender (male/female)
Age (mean ⫾ SD)
Patients with previous oral
EGD (%)
Gagging score (median
[interquartile])
Total
N-EGD
UTO-EGD
CO-EGD
P
1580
792/788
60.0 ⫾ 16
1111 (70)
727
350/377
59 ⫾ 16
504 (69)
599
309/290
60.0 ⫾ 15
438 (73)
254
133/121
61 ⫾ 16
169 (67)
ns*
ns†
ns*
2 [2–6]
2 [0–4]
4 [2–6]
4 [2–6]
<0.01‡
P (N
versus UTO)
P (N
versus CO)
P (UTO
versus CO)
<0.01§
<0.01§
ns§
*Chi-squared test, †One-factor analysis of variance, ‡Kruskal–Wallis test, §Mann–Whitney test. CO-EGD, conventional esophagogastroduodenoscopy; N-EGD, nasal esophagogastroduodenoscopy; UTO-EGD, ultrathin oral esophagogastroduodenoscopy.
performed using the SPSS for Windows (SPSS Japan
Inc., Tokyo, Japan). A P value less than 0.05 and a
correlation coefficient more than 0.4 were considered
significant.
RESULTS
Study patients
Among the 1580 patients enrolled, 752, 572, and 254
patients chose N-EGD, UTO-EGD, and CO-EGD,
respectively. However, since we failed transnasal
intubation in 25 patients (3.2%), 727, 599, and 254
patients were assigned to N-EGD, UTO-EGD, and
CO-EGD, respectively. Self-limiting epistaxis and
severe nasal pain as complications of N-EGD were
observed in eight (1.1%) and seven cases (1.0%),
respectively. Patients’ characteristics are shown in
Table 1. No significant difference was found in
gender, age and the number of patients with previous
oral endoscopy among the groups.
Diagnosis of HH
There was significant difference in the frequency distribution of the size of HH among three EGDs
(P < 0.05). When compared between the two groups,
the distribution in N-EGD was significantly different
from those in UTO-EGD and CO-EGD (P < 0.05,
respectively). There was no significant difference in
the distributions between UTO-EGD and CO-EGD.
The size of the hernia was significantly smaller in
N-EGD than those in two other per-oral endoscopies
(P < 0.05) (Table 3).
Diagnosis of BE
There was no significant difference in the frequency
distribution of the severity of BE among three EGDs
(Table 4).
Interrelation among GERD-associated diseases
There was no correlation among the distributions of
the severity of RE, the size of HH, and the severity of
BE in all three EGDs.
Diagnosis of RE
There were no significant differences in the frequency
distribution of the severity of RE among three EGDs
(Table 2).
Influence of gagging reflex on the diagnosis of GERD
The severity of gagging reflex was lowest in N-EGD
(Table 1). In all EGDs the severity of gagging reflexes
Table 2 Frequency distribution of the severity of RE in the three different endoscopies and interrelation between the severity of RE and
gagging as well as the other two GERD-associated diseases
LA grade (%)
Gagging score
EGD
N
M
A
B
C
D
Pa
With RE
Without RE
Pb
N
529
(72.8)
409
(68.2)
172
(67.7)
1110
(70.3)
107
(14.7)
112
(18.7)
41
(16.1)
260
(16.5)
61
(8.4)
58
(9.7)
30
(11.8)
149
(9.4)
21
(2.9)
11
(1.8)
10
(3.9)
42
(2.7)
6
(0.8)
7
(1.2)
1
(0.4)
14
(0.9)
3
(0.4)
2
(0.3)
0
(0)
5
(0.3)
ns
2 [0–6]
2 [0–4]
ns
4 [2–6]
4 [0–6]
ns
4 [2–6]
4 [2–6]
ns
2 [0–6]
2 [2–6]
ns
UTO
CO
Total
We showed LA grade N and LA grade M–D as without RE and with RE, respectively. Ns, not significant; Pa, Kruskal–Wallis test; Pb,
Mann-Whitney test; RE, reflux esophagitis.
© 2010 Copyright the Authors
Journal compilation © 2010, Wiley Periodicals, Inc. and the International Society for Diseases of the Esophagus
96 Diseases of the Esophagus
Table 3 Frequency distribution of the size of HH in the three different endoscopies and interrelation between HH grades and gagging
score as well as the other two GERD-associated diseases
HH grade (%)
Pb
Gagging score
EGD
0
1
2
3
Pa
N versus
UTO
N versus
CO
UTO
versus CO
N
UTO
CO
Total
407 (56)
297 (49.6)
122 (48.0)
830 (52.6)
171 (23.5)
160 (26.7)
70 (27.6)
397 (25.1)
119 (16.4)
111 (18.5)
48 (18.9)
278 (17.6)
30 (4.1)
31 (5.2)
14 (5.5)
75 (4.7)
<0.05
<0.05
<0.05
ns
With HH
Without
HH
Pb
4 [0–6]
4 [2–6]
4 [2–6]
4 [2–6]
2 [0–4]
2 [2–6]
2 [2–6]
2 [0–4]
P < 0.01
P < 0.01
P < 0.05
P < 0.01
BE, Barrett’s epithelium; HH, sliding esophageal hiatus hernia; Pa, Kruskal–Wallis test; Pb, Mann–Whitney test; RE, reflux esophagitis. We
showed HH grade 0 and HH grades 1–3 as without HH and with HH, respectively.
seemed to affect significantly the diagnosis of HH
(Table 3), however, no significant correlation was
found between the severity of gagging reflexes and the
diagnosis of RE or BE (Tables 2 and 4).
DISCUSSION
Recently, concerns have been reported regarding the
diagnosability of ultrathin EGD particularly in the
diagnosis of early gastric cancer.4–6 Similarly, there
might be some concerns regarding the utility of
ultrathin EGD in the diagnosis of GERD because the
high image resolution is also required to observe the
minimal changes of RE and esophageal palisade
vessels. We have shown here that there was no significant difference in the frequency distributions of
the severity of RE and BE among three EGDs, suggesting little disadvantage of an ultrathin endoscope
in the diagnosis of the GERD-related diseases. We
understand that the present study might have the
possible bias because we could not perform complete
randomization in the selection of endoscopy or the
crossover study design because of ethical problems.
Thus, we enrolled a large number of patients as possible to reduce the bias. Because no significant difference was found in patients’ characteristics including
experience of previous endoscopy, we believe that the
present study is reliable enough to assess the diagnos-
ability of each endoscopy. Our observation is supported by the previous reports that N-EGD may be
beneficial in examining esophageal diseases as the
procedure requires no sedation.10–12
In the diagnosis of HH, the evaluated size of the
hernia was smaller in N-EGD than those in two
other per-oral endoscopies. Since the high-grade
endoscopic image resolution was not necessary for
the diagnosis of HH, the difference in the insertion
routes of the endoscopes may affect the size of HH.
We have also shown that the diagnosis of HH was
affected significantly by the severity of gagging
reflexes that was lowest in N-EGD. These observations may lead to our proposal that gagging reflexes
induced by oral EGDs might cause an overestimation of HH and that the transnasal approach with
less gagging reflex is more suitable to know the
natural situation of EGJ. Future interest is to
compare the diagnosability of HH between N-EGD
and fluoroscopy, observing the effect of esophageal
peristalsis induced by swallowing.13
There was no significant difference in the frequency distribution of the severity among the three
EGDs in diagnosing of BE as well as RE. However,
the incidence of BE in the present study (approximately 32%) was significantly higher than that in the
nationwide survey of GERD in Japan (18% in BE
grade 1, 3% in BE grade 2, and 0.2% in BE grade 3)
(P < 0.01 by Kruskal–Wallis test).8 Such differences
Table 4 Frequency distribution of the severity of BE in the three different endoscopies and interrelation between BE grades and gagging
score as well as the other two GERD-associated diseases
BE grade (%)
EGD
N
UTO
CO
Total
0
1
Gagging score
2
3
P
With BE
Without BE
P
0.26
2 [0–4]
2 [0–4]
ns
4 [2–6]
4 [2–6]
ns
4 [2–6]
4 [2–6]
ns
2 [0–6]
2 [2–6]
ns
502
(69.1)
188
(25.9)
31
(4.3)
6
(0.8)
400
(66.8)
166
(65.4)
1068
(67.6)
150
(25)
61
(24)
399
(25.2)
46
(7.7)
26
(10.2)
103
(6.5)
3
(0.5)
1
(0.39)
10
(0.6)
P: Kruskal–Wallis test. We showed BE grade 0 and BE grade 1–3 as without BE and with BE, respectively. BE, Barrett’s epithelium; HH,
sliding esophageal hiatus hernia; ns, not significant; RE, reflux esophagitis.
© 2010 Copyright the Authors
Journal compilation © 2010, Wiley Periodicals, Inc. and the International Society for Diseases of the Esophagus
Diagnosability of transnasal EGD in GERD 97
may be caused by the difference in the observation
conditions, including the amount of air in the
stomach, breathing, and peristalsis.14,15 Our observation was obtained under the controlled conditions
regarding the insufflation of the stomach, breathing
and peristalsis. However, no information was available on such conditions in the Japan survey. For
instance, deep inspiration induces the extension of the
esophagus, making the observation of EGJ easier.
Thus, we suggest that observation of EGJ should be
performed under the controlled conditions including
the depth of breath. For such a purpose, N-EGD may
be useful because the method induces less gagging
reflexes and needs no sedation.
Although the diagnosis of BE can be made endoscopically by assessing BE lengths,16,20 biopsies are
sometimes required for the pathological confirmation
and assessment for dysplasia of BE. One might have
a concern that small biopsy specimens obtained by
N-EGD may affect the quality of the histopathologic
diagnosis. However, Saeian et al. have reported the
same reliability of N-EGD regarding the histologic
diagosis of BE as compared with CO-EGD.17
The definition of EGJ is prerequisite for the diagnosis of BE. In the previous studies in which EGJ was
defined as the proximal margin of the gastric folds
according to the Prague C and M criteria,16 BE has
been shown to be more frequent in patients with
HH.18,19 On the other hand, in the present study in
which EGJ was defined as the distal end of the lower
esophageal palisade vessels according to the Hoshihara’s criteria,20–22 no correlation was found between
the prevalence of HH and BE, similar to the report by
Kusano et al.21 Thus, the definition of EGJ may
largely affect the interrelation of these two diseases.
We recommend the Hoshihara’s criteria for the diagnosis of BE for the following reasons: (i) the criteria
makes the close observation of BE possible without
being affected by HH; and (ii) approximately 80% of
Western endoscopists were able to identify the end of
the lower esophageal palisade vessels.21 However,
irrespective of the EGJ definitions, once gagging
reflexes, uncontrolled breathing or peristalsis take
place, we may misidentify the positions of EGJ and
esophageal hiatus, which may link to the misdiagnosis of the GERD-associated diseases. N-EGD may be
advantageous than per-oral EGD not only because
transnasal approaches can reduce gagging reflexes
and uncontrolled breathing, but also because the
endoscopic image resolution of N-EGD is high
enough to recognize minimal changes in EGJ. We
have previously shown that N-EGD induced parasympathetic inhibition with less sympathetic stimulation than oral EGD.23 Such effects of N-EGD on
autonomic nervous system might reduce peristalsis,
which is also beneficial for the observation of EGJ,
although further studies is required to elucidate the
effect.
In conclusion, we have shown that N-EGD had an
equivalent performance in the diagnosis of RE and
BE compared with per-oral EGDs. Moreover, the
enlargement of HH induced by gagging reflexes was
minimal in N-EGD, resulting in its better performance in the diagnosis of BE. Therefore, we suggest
the better performance of N-EGD compared with
oral EGDs in the diagnosis of GERD-associated
diseases.
References
1 Mishima I, Adachi K, Arima N et al. Prevarence of endoscopically negative and positive gastroesophageal reflux disease in
the Japanese. Scand J Gastroenterol 2005; 40: 1005–9.
2 Kusano M, Shimoyama Y, Sugimoto S et al. Development and
evaluation of FSSG: frequency scale for the symptoms of
GERD. J Gastroenterol 2004; 39: 888–91.
3 Cameron A J, Lomboy C T, Pera M, Carpenter H A. Adenocarcinoma of the esophagogastric junction and Barrett’s
esophagus. Gastroenterology 1995; 109: 1541–6.
4 Toyoizumi H, Kaise M, Arakawa H et al. Ultrathin endoscopy
versus high-resolution endoscopy for diagnosing superficial
gastric neoplasia. Gastrointest Endosc 2009; 70: 240–5.
5 Horiuchi A, Nakayama Y, Hidaka N, Ichise Y, Kajiyama M,
Tanaka N. Prospective comparison between sedated highdefinition oral and unsedated ultrathin transnasal esophagogastroduodenoscopy in the same subjects: pilot study. Dig
Endosc 2009; 21: 24–8.
6 Hayashi Y, Yamamoto Y, Suganuma T et al. Comparison
of the diagnostic utility of the ultrathin endoscope and the
conventional endoscope in early gastric cancer screening.
Dige Endosc 2009; 21: 116–21.
7 Mori A, Fushimi N, Asano T et al. Cardiovascular tolerance in
unsedated upper gastrointestinal endoscopy: prospective randomized comparison between transnasal and conventional oral
procedures. Dig Endosc 2006; 18: 282–7.
8 Kawano T, Kouzu T, Ohara S, Kusano M. The prevalence of
Barrett’s mucosa in the Japanese (in Japanese with English
abstract). Gastroenterol Endosc 2005; 47: 951–61.
9 Kusano M, Hashizume K, Ehara Y, Shimoyama Y, Kawamura O, Mori M. Size of hiatus hernia correlates with severity
of kyphosis, not with obesity, in elderly Japanese women. J Clin
Gastroenterol 2008; 42: 345–50.
10 Falcone M T, Garrett C G, Slaughter J C, Vaezi M. Transnasal
esophagoscopy findings: interspecialty comparison. Otolaryngol Head Neck Surg 2009; 140: 812–15.
11 Andrus J G, Dolan R W, Anderson T D. Transnasal esophagoscopy: a high-yield diagnostic tool. Laryngoscope 2005; 115:
993–6.
12 Postma G N, Cohen J T, Belafsky P C et al. Transnasal esophagoscopy: revisited (over 700 consecutive cases). Laryngoscope
2005; 115: 321–3.
13 Kawai T, Yamagishi T, Yagi K et al. Impact of transnasal
ultrathin esophagogastroduodenoscopy (UT-EGD) in the
evaluation of esophageal peristaltic function. J Gastroenterol
Hepatol 2008; 23: 181–5.
14 Bergmann J J. Gastroesophageal reflux disease and Barrett’s
esophagus. Endoscopy 2005; 37: 8–18.
15 Amano Y, Ishimura N, Furuta K et al. Which landmark results
in a more consistent diagnosis of Barrett’s esophagus, the
gastric folds or the palisade vessels? Gastrointest Endosc 2006;
64: 206–11.
16 Sharma P, Dent J, Armstrong D et al. The development and
validation of an endoscopic grading system for Barrett’s
esophagus: the Prague C and M criteria. Gastroenterology
2006; 131: 1392–9.
17 Saeian K, Staff D M, Vasilopoulos S et al. Unsedated transnasal endoscopy accurately detects Barrett’s metaplasia and dysplasia. Gastrointest Endosc 2002; 56: 472–8.
18 Okita K, Amano Y, Takahashi Y et al. Barrett’s esophagus
in Japanese patients: its prevalence, form, and elongation.
J Gastroenterol 2008; 43: 928–34.
© 2010 Copyright the Authors
Journal compilation © 2010, Wiley Periodicals, Inc. and the International Society for Diseases of the Esophagus
98 Diseases of the Esophagus
19 Akiyama T, Inamori M, Akimoto K et al. Gender differences
in the age-stratified prevalence of erosive esophagitis and
Barrett’s epithelium in Japan. Hapaogastroenterol 2009; 56:
144–8.
20 Hoshihara Y, Kogure T, Yamamoto T, Hashimoto M, Hoteya
O. Endoscopic diagnosis of Barrett’s esophagus (in Japanese
with English abstract). Nippon Rinsho 2005; 63: 1394–8.
21 Kusano C, Kaltenbach T, Shimazu T, Soetikno R, Gotoda T.
Can Western endoscopists identify the end of the lower esoph-
ageal palisade vessels as a landmark of esophagogastric junction? J Gastroenterol 2009; 44: 842–6.
22 Ogiya K, Kawano T, Ito E et al. Lower esophageal palisade
vessels and the definition of Barrett’s esophagus. Dis Esophagus 2008; 21: 645–9.
23 Mori A, Ohashi N, Tatebe H et al. Autonomic nervous function in upper gastrointestinal endoscopy: a prospective randomized comparison between transnasal and oral procedures. J
Gastroenterol 2008; 43: 38–44.
© 2010 Copyright the Authors
Journal compilation © 2010, Wiley Periodicals, Inc. and the International Society for Diseases of the Esophagus