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Unsedated ultrathin EGD by using a 5.2-mm–diameter videoscope: evaluation of acceptability and diagnostic accuracy
ORIGINAL ARTICLE: Clinical Endoscopy
Unsedated ultrathin EGD by using a 5.2-mm–diameter videoscope: evaluation of acceptability and diagnostic accuracy Akira Horiuchi, MD, Yoshiko Nakayama, MD Komagane, Japan
Background: This study was designed to assess the acceptability and the diagnostic accuracy of unsedated ultrathin EGD (uUT-EGD) by using a newly developed 5.2-mm-diameter videoscope compared with unsedated small-caliber EGD (uSC-EGD) by using a 6.5-mm–diameter videoscope or sedated conventional EGD (sC-EGD) by using a 9.0-mm–diameter videoscope. Design: First, 80 patients who had undergone uSC-EGD approximately 1 year earlier were randomized to receive uUT-EGD (n Z 40) or uSC-EGD (n Z 40). Endoscopist satisfaction and patient comfort were assessed by using a 10-cm visual analog scale. Patient comfort level was compared with that of the previous uSC-EGD. Second, 40 patients who had undergone sC-EGD within the previous 1.5 years underwent uUT-EGD. The optical quality and EGD findings of uUT-EGD were compared with those of the previous sC-EGD. Last, in the 80 patients undergoing uUT-EGD, the ability to identify a validated endoscopic marker, the rearrangement of collecting venues (RAC) pattern, for no Helicobacter pylori, was compared with the results of a 13C-urea breath test or H pylori stool antigen test. Setting: Showa Inan General Hospital, Komagane, Japan. Patients: A total of 120 patients who undergo EGD every year as part of a gastric cancer surveillance program. Results: The patient comfort level of uUT-EGD was significantly better than that of uSC-EGD (P !.0001). The optical quality of the endoscopic images and the EGD findings of uUT-EGD were similar to those of the previous sC-EGD. The overall sensitivity, specificity, and accuracy of the RAC pattern in uUT-EGD in recognizing H pylori– uninfected patients were 90%, 100%, and 93%, respectively. The interobserver agreement for RAC was good (k Z 0.42). Conclusions: The use of a 5.2-mm–diameter videoscope is expected to enhance the patient acceptance of unsedated EGD. (Gastrointest Endosc 2006;64:868-73.)
Small-diameter endoscopes, including fiberoptic scopes and videoscopes, have been reported to be useful for unsedated EGD, irrespective of the insertion routes.1-6 However, despite its potential safety and cost benefits, unsedated EGD has not gained wide acceptance in the United States.7 Recently, a 5.2-mm–diameter videoscope was developed to facilitate acceptance of unsedated EGD based on the notion that the reduction in the endoscope diameter would improve the acceptance of unsedated EGD, provided the diagnostic accuracy is comparable with conventional EGD. This study was designed to assess the acceptability and the diagnostic accuracy of unsedated ultrathin EGD (uUT-EGD) by using the 5.2-mm–diameter videoscope compared with unsedated small-caliber EGD
(uSC-EGD) by using a 6.5-mm–diameter videoscope or sedated conventional EGD (sC-EGD) by using a 9.0-mmdiameter videoscope. It has been reported that a validated endoscopic marker for the absence of active Helicobacter pylori infection, the rearrangement of collecting venues (RAC) pattern, enables the H pylori–negative normal stomach to be identified by using standard videoscopes.8-10 Therefore, we used the ability to correctly categorize the presence or the absence of the RAC pattern by using the 5.2-mm–diameter videoscope as a measure of its optical quality and suitability for identifying subtle EGD findings.
PATIENTS AND METHODS
Copyright ª 2006 by the American Society for Gastrointestinal Endoscopy 0016-5107/$32.00 doi:10.1016/j.gie.2006.01.025
The study was conducted from October 2004 to March 2005. A total of 120 patients who undergo EGD every year as part of a gastric cancer surveillance program were
868 GASTROINTESTINAL ENDOSCOPY Volume 64, No. 6 : 2006
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Horiuchi & Nakayama
included in this study. Exclusion criteria included failure to remember the previous EGD, prior gastric surgery, active or severe cardiopulmonary disease, coagulopathy, active GI bleeding, and planned sequential endoscopic procedures. The examinations were performed by 1 of 2 endoscopists, both of whom are experienced in the performance of EGD with a small-caliber instrument. Patients received a pharyngeal anesthesia with lidocaine. Sedative medication (0.08 mg/kg midazolam) was administered intravenously in sC-EGD. All patients, in the left lateral position, underwent EGD via an oral route. The institutional review board for human investigation of our hospital approved the study protocol, and all participants gave written informed consent.
Study 1 Eighty patients who had undergone uSC-EGD with the 6.5-mm–diameter videoscope (GIF-XP260; Olympus Optical Co, Ltd, Tokyo, Japan) approximately 1 year earlier were randomized to undergo uUT-EGD with the 5.2-mm– diameter videoscope (GIF-N260; Olympus)(n Z 40) or uSC-EGD (n Z 40). Randomization (according to a table of random numbers) took place by coded assignment to either uUT-EGD or uSC-EGD. The endoscopists considered the examination complete if they were able to adequately inspect the upper-GI tract. The EGD procedure time was defined as the time in minutes from taking the first image of the upper portion of the esophagus to the time when the final image was taken. Vital signs, medication dosages, endoscopic findings, and adverse events were recorded. Heart rate and oxygen saturation levels were recorded during the procedure. If oxygen saturation was less than 90%, supplemental oxygen was supplied. The levels of endoscopist satisfaction and patient comfort were assessed by using a 10-cm visual analog scale (VAS), where 10 is excellent and 1 is poor.11 Patients were asked to describe whether their comfort level was better, the same, or worse than their comfort level during the previous uSC-EGD. In addition, patients were asked if they would repeat the same procedure (yes/no).
Study 2 Forty patients who had undergone sC-EGD with the 9.0-mm–diameter videoscope (GIF-XQ240; Olympus) within the previous 1.5 years underwent uUT-EGD. The endoscopic images and EGD findings in both uUT-EGD and the previous sC-EGD were independently evaluated by 2 endoscopists who were blinded to the patients’ clinical histories or H pylori status. The optical quality of the instruments in the lower esophagus, the antrum and the body of the stomach, and the duodenal bulb was evaluated by using a 10-cm VAS, where 10 is excellent and 1 is poor.11 Interobserver agreement on the presence/ absence of each endoscopic finding in uUT-EGD was estimated by the kappa (k) statistic. www.giejournal.org
Unsedated ultrathin EGD
Capsule Summary What is already known on this topic d
d
Unsedated EGD with small-diameter endoscopes reduces the uncommon but serious cardiopulmonary complications of sedation. A 5.2-mm–diameter videoscope has been developed to facilitate acceptance of unsedated EGD.
What this study adds to our knowledge d
d
In a randomized trial, the patient comfort level during unsedated, ultrathin EGD when using the 5.2-mm–diameter videoscope was significantly better than that of a previous unsedated small-caliber EGD with a 6.5-mm–diameter videoscope. The optical quality of the ultrathin endoscopic images was similar to those of the conventional procedure.
Study 3 All 80 patients who underwent uUT-EGD in studies 1 and 2 were examined for the presence of RAC. Magnified views of RAC, obtained by using a magnifying endoscope at 80-fold magnification, showed its characteristic features: collecting venules with a starfish-like appearance, true capillaries forming a network, and gastric pits that look like pinholes. These structures originate from the microvascular system of the mucosa of the body of the normal stomach. True capillaries surround each of the glands and connect to the collecting venules.8 At the point where the lower corpus lesser curvature was recognized at the 12-o’clock position, the videoscope tip was deflected upward, providing a direct view of the gastric membrane of the lower corpus lesser curvature near the incisura. Close observation consisted of endoscopic observation of the gastric mucosa viewed at a distance of approximately 5 mm between the tip of the instrument and the gastric surface. A RAC-positive pattern was defined as numerous minute red points of very similar size seen at regular intervals across the entire monitor (Fig. 1). If the red points were irregularly present or absent, the RAC pattern was scored as negative (Fig. 2).8,9 The determination of the RAC pattern was independently carried out by 2 endoscopists who were blinded to the patients’ clinical histories or H pylori status. Patients were classified as H pylori–positive, if the result of their 13Curea breath test or stool antigen test was positive. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of the RAC pattern in recognizing H pylori–negative were calculated, by using the result of their 13C-urea breath test or stool antigen test as a reference.
Instruments The GIF-XQ240 and GIF-XP260 videoscopes (Olympus) have an insertion diameter of 9.0 or 6.5 mm, an accessory Volume 64, No. 6 : 2006 GASTROINTESTINAL ENDOSCOPY 869
Unsedated ultrathin EGD
Figure 1. A, Endoscopic image of a whole view of the body of the normal stomach. B, Typical RAC pattern under close observation view of the lower lesser curvature of the body. Numerous minute red points of almost similar size were seen at regular intervals all over the monitor view at the lesser curvature near the incisura.
channel diameter of 2.8 or 2 mm, a total length of 1335 mm, and a working length of 1030 mm. The newly developed GIF-N260 videoscope used for the uUT-EGD is a forward-viewing upper-GI videoscope with an ultraminiature, high-resolution charged-coupled device with a 120 field of view. It has a 5.2-mm insertion diameter, and a biopsy channel of 2 mm. It has a tip deflection capability of 210/120 up/down in a single plane. Other features of the 5.2-mm videoscope are almost the same as those of other standard videoscopes.
Statistical analysis A comparison between the 2 study groups was done by using c2 statistics for categorical variables. The Fisher exact test was used when the numbers were small. For continuous variables, the Student t test was applied. A P value less than .05 was taken as indicative of significant differences. The k statistic was used to compare the assessments of the 2 endoscopists. A k equal to 0 indicated no 870 GASTROINTESTINAL ENDOSCOPY Volume 64, No. 6 : 2006
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Figure 2. A, Endoscopic image of a whole view of the body of H pylori gastritis. B, A typical close observation view of a RAC-negative case is shown. The red points were absent or irregularly present.
agreement between the 2 endoscopists beyond that expected by chance. A k greater than 0.75 was considered excellent reproducibility, a k between 0.40 and 0.75 denoted good reproducibility, and a k less than 0.40 indicated poor to marginal reproducibility. To detect a 2-cm (20%) VAS difference in overall patient satisfaction between the 2 groups by using a 2-sided alpha of 0.05 and a beta of 0.2, the required number of patients in each arm was estimated to be 40. All statistical evaluation was performed by using SPSS version 12.0J software (SPSS Japan Inc, Tokyo, Japan).
RESULTS Study 1 The uUT-EGD and uSC-EGD groups were evenly matched for age and sex (Table 1). All patients completed the endoscopic examinations. There was no significant difference in endoscopist satisfaction score, patient comfort score, or willingness to repeat EGD in the same manner www.giejournal.org
Horiuchi & Nakayama
Unsedated ultrathin EGD
TABLE 1. Endoscopist and patient assessment with uUT-EGD vs uSC-EGD
TABLE 2. Optical quality of the instruments in uUT-EGD compared with the previous SC-EGD
uUT-EGD (N Z 40)
uSC-EGD (N Z 40)
P value
Age, y*
56 G 13
54 G 12
.68
Age, y*
57 G 17
Sex, % female
45
38
.65
Sex, % female
40
Completed EGD, %
100
100
EGD procedure time, min *,y
5.2 G 0.7
4.9 G 0.8
.21
Endoscopist satisfaction score*,y
7.7 G 1.8
8.5 G 2.2
.88
Patient comfort score*,y
8.2 G 1.6
7.3 G 1.9
.78
Lower esophagus
7.5 G 2.1/7.3 G 2.0
.84
Antrum of the stomach
7.2 G 1.9/7.3 G 1.9
.77
Body of the stomach
6.5 G 2.0/7.3 G 1.9
.76
Duodenal bulb
7.7 G 2.1/7.2 G 2.2
.55
*Values represent mean and standard deviation. yScale 1-10, where 10 is excellent and 1 is poor; mean values of optical quality evaluated by 2 endoscopists are shown.
32 (80%)
12 (30%)
!.0001
25 (62%)
!.0001
Same
7 (17.5%)
Worse
1 (2.5%)
3 (7.5%)
.62
36 (90%)
33 (83%)
.52
Willing to repeat the same procedure
P value
Optical qualityy
Patient comfort in comparison with previous sC-EGD Better
uUT-EGD/SC-EGD (N Z 40)
*Values represent mean and standard deviation. yScale 1-10, where 10 is excellent and 1 is poor.
between the 2 groups. However, 80% (32/40) of patients who underwent uUT-EGD considered that the procedure was better than the previous uSC-EGD (vs 30% [12/40] of those who underwent a second uSC-EGD), suggesting that the use of a 5.2-mm–diameter videoscope may be superior to that of a 6.5-mm–diameter videoscope with regard to patient acceptance.
H pylori status was negative, whereas H pylori was positive in 24 of 29 (Endoscopist 1) or 30 (Endoscopist 2) RAC-negative patients. No false-positive findings were reported by either endoscopist. Based on the assessment of the 2 endoscopists, the overall sensitivity, specificity, PPV, NPV, and accuracy for the RAC pattern in recognizing H pylori–uninfected patients were 90%, 100%, 100%, 81%, and 93%, respectively (Table 4). The interobserver agreement for RAC was good (k Z 0.42).
DISCUSSION
In the 51 (Endoscopist 1) or 50 (Endoscopist 2) RAC– positive patients assessed by each of the 2 endoscopists,
Unsedated EGD has been shown to reduce the uncommon but substantial cardiopulmonary complications associated with sedated EGD.12-14 In addition, patients can return to work directly after the procedure and do not require a driver, resulting in a marked decrease in total costs associated with the procedure.6,14 However, most patients in the United States still find unsedated EGD when using these small-diameter instruments unacceptable, as evidenced by the up to 40% refusal rate of patients who were asked to participate in these studies.14 Endoscopists also prefer sedated EGD by using standard endoscopes to unsedated EGD when using small-diameter endoscopes.14 A 5.2-mm–diameter videoscope was developed with the goal of making unsedated EGD more acceptable. However, it is unclear whether small-diameter endoscopes produce a small but significant decrease in diagnostic accuracy and sensitivity.14 The specifications of the new videoscope are similar to conventional videoscopes, with the exception that it has only unidirectional up/down tip deflection. The study was conducted within the context that many Japanese undergo EGD at the same institution every year as part of a surveillance program to detect early gastric cancer. These results were based on the fact that
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Volume 64, No. 6 : 2006 GASTROINTESTINAL ENDOSCOPY 871
Study 2 The endoscopists’ evaluation of the optical quality of the instruments based on the ability to identify endoscopic finding is shown in Table 2. The mean score of optical quality assessed by 2 endoscopists was not significantly different between uUT-EGD and the previous sC-EGD. Although EGD findings, such as hiatal hernia, raised erosion, gastric submucosal tumor, and fundic glands polyp, were different between uUT-EGD and the previous sC-EGD, interobserver agreement for each endoscopic finding in uUT-EGD was perfect (k Z 1.0) between the 2 endoscopists (Table 3). The diagnostic accuracy of the uUT-EGD seemed to be similar to that of the previous sC-EGD.
Study 3
Unsedated ultrathin EGD
Horiuchi & Nakayama
TABLE 3. Endoscopic assessments by 2 independent endoscopists in uUT-EGD compared with the previous sC-EGD Endoscopist 1
Endoscopist 2
uUT-EGD/sC-EGD (N Z 40)
uUT-EGD/sC-EGD (N Z 40)
Kappa*
Esophageal SMT
1/1
1/1
1.0
Esophageal varices
1/1
1/1
1.0
Esophagitis
4/3
3/3
0.35
Hiatal hernia
5/8
5/8
1.0
RAC-positive
11/11
10/10
0.40
Raised erosion
3/2
3/2
1.0
GU scar
1/1
1/1
1.0
Gastric SMT
1/0
1/0
1.0
Fundic glands polyp
5/3
5/3
1.0
Gastric hyperplastic polyp
1/1
1/1
1.0
DU scar
1/1
1/1
1.0
Endoscopic features
SMT, Submucosal tumor; RAC, rearrangement of collecting venues; GU, gastric ulcer; DU, duodenal ulcer. *Interobserver agreement (Kappa statistics) on the presence or absence of each endoscopic finding in UT-EGD is shown.
most patients are able to remember the comfort levels of their previous EGDs; however, confirmation is needed when using a protocol where both studies are done at a closer interval. The 5.2-mm–diameter videoscope can be inserted perorally or transnasally.15 In a number of randomized controlled trials comparing transnasal with peroral unsedated EGD, peroral unsedated ultrathin EGD was the method preferred by both patients and endoscopists.16-18 In addition, the usefulness of unsedated esophagoscopy with a 4-mm–diameter endoscope was reported.19,20 However, the 4-mm–diameter endoscope did not suit EGD. In this study, all uUT-EGDs were performed perorally to allow direct comparison with the previous EGD. Eighty percent of the patients who underwent uUT-EGD considered the
procedure better than the previous uSC-EGD (vs 30% of those who underwent a second uSC-EGD), suggesting that the use of a 5.2-mm–diameter videoscope may be superior to the 6.5-mm–diameter videoscope with regard to patient acceptance. We attempted to evaluate the diagnostic accuracy of the 5.2-mm–diameter videoscope objectively by comparing the results (endoscopic photographs) of the uUT-EGD with those of the previous sC-EGD. We also used the RAC pattern, and the uUT-EGD was demonstrated to be essentially equivalent to the larger-diameter endoscope for the endoscopic detection of absence of H pylori infection (Tables 3 and 4). The data that the agreement was perfect (k Z 1.0) for 2 endoscopists reveal that the diagnostic accuracy of the 5.2-mm–diameter videoscope was within the acceptable range for detecting upper-GI diseases. Because tip deflection of the small-diameter endoscope is restricted to a unidirectional up-and-down motion, tip maneuverability requires rotation of the endoscope. This potential limitation did not prevent the endoscopist from obtaining a clear whole view at the upper GI (Table 2). The intensity of the light delivered and the airinsufflation ability from the small-diameter videoscope were not noticeably different from standard videoscopes. The results of the present study highlight the trade-offs between the potential benefits of unsedated EGD with slim endoscopes and the potential for a decrease in maneuverability and diagnostic accuracy associated with smallercaliber endoscopes. The data support the notion that adoption of this videoscope in primary care facilities in which the use of sedation is restricted should be encouraged.
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TABLE 4. Association of presence or absence of RAC with H pylori infection in uUT-EGD: comparison between 2 endoscopists RAC (C)/ H pylori (–)
Se (%)
Sp (%)
PPV (%)
NPV (%)
Accuracy (%)
Endoscopist 1
91
100
100
83
94
Endoscopist 2
89
100
100
80
93
Both endoscopists
90
100
100
81
93
RAC, Rearrangement of collecting venues; Se, sensitivity; Sp, specificity; PPV, positive predictive value; NPV, negative predictive value.
Horiuchi & Nakayama
ACKNOWLEDGMENTS We thank Masashi Kajiyama, Hideyasu Fujii, Hamako Hara, Chiemi Tanaka, and Satoko Takezawa for their dedicated technical assistance. As well, we wish to thank Torao Sakamoto (Showa Inan General Hospital) for his assistance with the statistical analysis. DISCLOSURE None of the authors work for Olympus Optical, receive support from the company, or have financial interest in the company.
REFERENCES 1. Dean R, Dua K, Massey B, et al. A comparative study of unsedated transnasal esophagogastroduodenoscopy and conventional EGD. Gastrointest Endosc 1996;44:422-4. 2. Zaman A, Hapke R, Sahagun G, et al. Unsedated peroral endoscopy with a video ultrathin endoscope: patient acceptance, tolerance, and diagnostic accuracy. Am J Gastroenterol 1998;93:1260-3. 3. Dumortier J, Ponchon T, Scoazec JY, et al. Prospective evaluation of transnasal esophagogastroduodenoscopy: feasibility and study on performance and tolerance. Gastrointest Endosc 1999;49:285-91. 4. Sorbi D, Gostout CJ, Henry J, et al. Unsedated small-caliber esophagogastroduodenoscopy (EGD) versus conventional EGD: a comparative study. Gastroenterology 1999;117:1301-7. 5. Mulcahy HE, Riches A, Kiely M, et al. A prospective controlled trial of an ultrathin versus a conventional endoscope in unsedated upper gastrointestinal endoscopy. Endoscopy 2001;33:311-6. 6. Garcia RT, Cello JP, Nguyen MH, et al. Unsedated ultrathin EGD is well accepted when compared with conventional sedated EGD: a multicenter randomized trial. Gastroenterology 2003;125:1606-12. 7. Waye JD. Worldwide use of sedation and analgesia for upper intestinal endoscopy. Gastrointest Endosc 1999;50:888-91. 8. Yagi K, Nakamura A, Sekine A. Characteristic endoscopic and magnified endoscopic findings in the normal stomach without Helicobacter pylori infection. J Gastroenterol Hepatol 2002;17:39-45.
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Unsedated ultrathin EGD 9. Nakayama Y, Horiuchi A, Kumagai T, et al. Discrimination of normal gastric mucosa from Helicobacter pylori gastritis using standard endoscopes and a single observation site: studies in children and young adults. Helicobacter 2004;9:95-9. 10. Kashiwagi H. Ulcers and gastritis. Endoscopy 2005;37:110-5. 11. Singer AJ, Thodes HC Jr. Determination of the minimally clinically significant difference on a patient visual analog satisfaction scale. Acad Emerg Med 1998;5:1007-11. 12. Lieberman DA, Wuerker CK, Katon RM. Cardiopulmonary risk of esophagogastroduodenoscopy: role of endoscope diameter and systemic sedation. Gastroenterology 1985;88:468-72. 13. Bell GD. Preparation, premedication, and surveillance. Endoscopy 2004;36:23-31. 14. Sorbi D, Chak A. Unsedated EGD. Gastrointest Endosc 2003;58:102-10. 15. Shaker R, Saeian K. Unsedated transnasal laryngo-esophagogastroduodenoscopy: an alternative to conventional endoscopy. Am J Med 2001;111(Suppl 8A):153S-6S. 16. Craig A, Hanlon J, Dent J, et al. A comparison of transnasal and transoral endoscopy with small-diameter endoscopes in unsedated patients. Gastrointest Endosc 1999;49:292-6. 17. Zaman A, Hahn M, Hapke R, et al. A randomized trial of peroral versus transnasal unsedated endoscopy using an ultrathin videoendoscope. Gastrointest Endosc 1999;49:279-84. 18. Wilkins T, Brewster A, Lammers J. Comparison of thin versus standard esophagogastroduodenoscopy. J Fam Pract 2002;51:625-9. 19. Catanzaro A, Faulx A, Isenberg GA, et al. Prospective evaluation of 4mm diameter endoscopes for esophagoscopy in sedated and unsedated patients. Gastrointest Endosc 2003;57:300-4. 20. Thota PN, Zuccaro G Jr, Vargo JJ 2nd, et al. A randomized prospective trial comparing unsedated esophagoscopy via transnasal and transoral routes using a 4-mm video endoscope with conventional endoscopy with sedation. Endoscopy 2005;37:559-65.
Received September 26, 2005. Accepted January 2, 2006. Current affiliations: Department of Gastroenterology (A.H.) and Pediatrics (Y.N.), Showa Inan General Hospital, Komagane, Japan. Reprint requests: Akira Horiuchi, MD, Department of Gastroenterology, Showa Inan General Hospital, 3230 Akaho, Komagane 399-4191, Japan.
Volume 64, No. 6 : 2006 GASTROINTESTINAL ENDOSCOPY 873
Unsedated ultrathin EGD by using a 5.2-mm–diameter videoscope: evaluation of acceptability and diagnostic accuracy Akira Horiuchi, MD, Yoshiko Nakayama, MD Komagane, Japan
Background: This study was designed to assess the acceptability and the diagnostic accuracy of unsedated ultrathin EGD (uUT-EGD) by using a newly developed 5.2-mm-diameter videoscope compared with unsedated small-caliber EGD (uSC-EGD) by using a 6.5-mm–diameter videoscope or sedated conventional EGD (sC-EGD) by using a 9.0-mm–diameter videoscope. Design: First, 80 patients who had undergone uSC-EGD approximately 1 year earlier were randomized to receive uUT-EGD (n Z 40) or uSC-EGD (n Z 40). Endoscopist satisfaction and patient comfort were assessed by using a 10-cm visual analog scale. Patient comfort level was compared with that of the previous uSC-EGD. Second, 40 patients who had undergone sC-EGD within the previous 1.5 years underwent uUT-EGD. The optical quality and EGD findings of uUT-EGD were compared with those of the previous sC-EGD. Last, in the 80 patients undergoing uUT-EGD, the ability to identify a validated endoscopic marker, the rearrangement of collecting venues (RAC) pattern, for no Helicobacter pylori, was compared with the results of a 13C-urea breath test or H pylori stool antigen test. Setting: Showa Inan General Hospital, Komagane, Japan. Patients: A total of 120 patients who undergo EGD every year as part of a gastric cancer surveillance program. Results: The patient comfort level of uUT-EGD was significantly better than that of uSC-EGD (P !.0001). The optical quality of the endoscopic images and the EGD findings of uUT-EGD were similar to those of the previous sC-EGD. The overall sensitivity, specificity, and accuracy of the RAC pattern in uUT-EGD in recognizing H pylori– uninfected patients were 90%, 100%, and 93%, respectively. The interobserver agreement for RAC was good (k Z 0.42). Conclusions: The use of a 5.2-mm–diameter videoscope is expected to enhance the patient acceptance of unsedated EGD. (Gastrointest Endosc 2006;64:868-73.)
Small-diameter endoscopes, including fiberoptic scopes and videoscopes, have been reported to be useful for unsedated EGD, irrespective of the insertion routes.1-6 However, despite its potential safety and cost benefits, unsedated EGD has not gained wide acceptance in the United States.7 Recently, a 5.2-mm–diameter videoscope was developed to facilitate acceptance of unsedated EGD based on the notion that the reduction in the endoscope diameter would improve the acceptance of unsedated EGD, provided the diagnostic accuracy is comparable with conventional EGD. This study was designed to assess the acceptability and the diagnostic accuracy of unsedated ultrathin EGD (uUT-EGD) by using the 5.2-mm–diameter videoscope compared with unsedated small-caliber EGD
(uSC-EGD) by using a 6.5-mm–diameter videoscope or sedated conventional EGD (sC-EGD) by using a 9.0-mmdiameter videoscope. It has been reported that a validated endoscopic marker for the absence of active Helicobacter pylori infection, the rearrangement of collecting venues (RAC) pattern, enables the H pylori–negative normal stomach to be identified by using standard videoscopes.8-10 Therefore, we used the ability to correctly categorize the presence or the absence of the RAC pattern by using the 5.2-mm–diameter videoscope as a measure of its optical quality and suitability for identifying subtle EGD findings.
PATIENTS AND METHODS
Copyright ª 2006 by the American Society for Gastrointestinal Endoscopy 0016-5107/$32.00 doi:10.1016/j.gie.2006.01.025
The study was conducted from October 2004 to March 2005. A total of 120 patients who undergo EGD every year as part of a gastric cancer surveillance program were
868 GASTROINTESTINAL ENDOSCOPY Volume 64, No. 6 : 2006
www.giejournal.org
Horiuchi & Nakayama
included in this study. Exclusion criteria included failure to remember the previous EGD, prior gastric surgery, active or severe cardiopulmonary disease, coagulopathy, active GI bleeding, and planned sequential endoscopic procedures. The examinations were performed by 1 of 2 endoscopists, both of whom are experienced in the performance of EGD with a small-caliber instrument. Patients received a pharyngeal anesthesia with lidocaine. Sedative medication (0.08 mg/kg midazolam) was administered intravenously in sC-EGD. All patients, in the left lateral position, underwent EGD via an oral route. The institutional review board for human investigation of our hospital approved the study protocol, and all participants gave written informed consent.
Study 1 Eighty patients who had undergone uSC-EGD with the 6.5-mm–diameter videoscope (GIF-XP260; Olympus Optical Co, Ltd, Tokyo, Japan) approximately 1 year earlier were randomized to undergo uUT-EGD with the 5.2-mm– diameter videoscope (GIF-N260; Olympus)(n Z 40) or uSC-EGD (n Z 40). Randomization (according to a table of random numbers) took place by coded assignment to either uUT-EGD or uSC-EGD. The endoscopists considered the examination complete if they were able to adequately inspect the upper-GI tract. The EGD procedure time was defined as the time in minutes from taking the first image of the upper portion of the esophagus to the time when the final image was taken. Vital signs, medication dosages, endoscopic findings, and adverse events were recorded. Heart rate and oxygen saturation levels were recorded during the procedure. If oxygen saturation was less than 90%, supplemental oxygen was supplied. The levels of endoscopist satisfaction and patient comfort were assessed by using a 10-cm visual analog scale (VAS), where 10 is excellent and 1 is poor.11 Patients were asked to describe whether their comfort level was better, the same, or worse than their comfort level during the previous uSC-EGD. In addition, patients were asked if they would repeat the same procedure (yes/no).
Study 2 Forty patients who had undergone sC-EGD with the 9.0-mm–diameter videoscope (GIF-XQ240; Olympus) within the previous 1.5 years underwent uUT-EGD. The endoscopic images and EGD findings in both uUT-EGD and the previous sC-EGD were independently evaluated by 2 endoscopists who were blinded to the patients’ clinical histories or H pylori status. The optical quality of the instruments in the lower esophagus, the antrum and the body of the stomach, and the duodenal bulb was evaluated by using a 10-cm VAS, where 10 is excellent and 1 is poor.11 Interobserver agreement on the presence/ absence of each endoscopic finding in uUT-EGD was estimated by the kappa (k) statistic. www.giejournal.org
Unsedated ultrathin EGD
Capsule Summary What is already known on this topic d
d
Unsedated EGD with small-diameter endoscopes reduces the uncommon but serious cardiopulmonary complications of sedation. A 5.2-mm–diameter videoscope has been developed to facilitate acceptance of unsedated EGD.
What this study adds to our knowledge d
d
In a randomized trial, the patient comfort level during unsedated, ultrathin EGD when using the 5.2-mm–diameter videoscope was significantly better than that of a previous unsedated small-caliber EGD with a 6.5-mm–diameter videoscope. The optical quality of the ultrathin endoscopic images was similar to those of the conventional procedure.
Study 3 All 80 patients who underwent uUT-EGD in studies 1 and 2 were examined for the presence of RAC. Magnified views of RAC, obtained by using a magnifying endoscope at 80-fold magnification, showed its characteristic features: collecting venules with a starfish-like appearance, true capillaries forming a network, and gastric pits that look like pinholes. These structures originate from the microvascular system of the mucosa of the body of the normal stomach. True capillaries surround each of the glands and connect to the collecting venules.8 At the point where the lower corpus lesser curvature was recognized at the 12-o’clock position, the videoscope tip was deflected upward, providing a direct view of the gastric membrane of the lower corpus lesser curvature near the incisura. Close observation consisted of endoscopic observation of the gastric mucosa viewed at a distance of approximately 5 mm between the tip of the instrument and the gastric surface. A RAC-positive pattern was defined as numerous minute red points of very similar size seen at regular intervals across the entire monitor (Fig. 1). If the red points were irregularly present or absent, the RAC pattern was scored as negative (Fig. 2).8,9 The determination of the RAC pattern was independently carried out by 2 endoscopists who were blinded to the patients’ clinical histories or H pylori status. Patients were classified as H pylori–positive, if the result of their 13Curea breath test or stool antigen test was positive. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of the RAC pattern in recognizing H pylori–negative were calculated, by using the result of their 13C-urea breath test or stool antigen test as a reference.
Instruments The GIF-XQ240 and GIF-XP260 videoscopes (Olympus) have an insertion diameter of 9.0 or 6.5 mm, an accessory Volume 64, No. 6 : 2006 GASTROINTESTINAL ENDOSCOPY 869
Unsedated ultrathin EGD
Figure 1. A, Endoscopic image of a whole view of the body of the normal stomach. B, Typical RAC pattern under close observation view of the lower lesser curvature of the body. Numerous minute red points of almost similar size were seen at regular intervals all over the monitor view at the lesser curvature near the incisura.
channel diameter of 2.8 or 2 mm, a total length of 1335 mm, and a working length of 1030 mm. The newly developed GIF-N260 videoscope used for the uUT-EGD is a forward-viewing upper-GI videoscope with an ultraminiature, high-resolution charged-coupled device with a 120 field of view. It has a 5.2-mm insertion diameter, and a biopsy channel of 2 mm. It has a tip deflection capability of 210/120 up/down in a single plane. Other features of the 5.2-mm videoscope are almost the same as those of other standard videoscopes.
Statistical analysis A comparison between the 2 study groups was done by using c2 statistics for categorical variables. The Fisher exact test was used when the numbers were small. For continuous variables, the Student t test was applied. A P value less than .05 was taken as indicative of significant differences. The k statistic was used to compare the assessments of the 2 endoscopists. A k equal to 0 indicated no 870 GASTROINTESTINAL ENDOSCOPY Volume 64, No. 6 : 2006
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Figure 2. A, Endoscopic image of a whole view of the body of H pylori gastritis. B, A typical close observation view of a RAC-negative case is shown. The red points were absent or irregularly present.
agreement between the 2 endoscopists beyond that expected by chance. A k greater than 0.75 was considered excellent reproducibility, a k between 0.40 and 0.75 denoted good reproducibility, and a k less than 0.40 indicated poor to marginal reproducibility. To detect a 2-cm (20%) VAS difference in overall patient satisfaction between the 2 groups by using a 2-sided alpha of 0.05 and a beta of 0.2, the required number of patients in each arm was estimated to be 40. All statistical evaluation was performed by using SPSS version 12.0J software (SPSS Japan Inc, Tokyo, Japan).
RESULTS Study 1 The uUT-EGD and uSC-EGD groups were evenly matched for age and sex (Table 1). All patients completed the endoscopic examinations. There was no significant difference in endoscopist satisfaction score, patient comfort score, or willingness to repeat EGD in the same manner www.giejournal.org
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Unsedated ultrathin EGD
TABLE 1. Endoscopist and patient assessment with uUT-EGD vs uSC-EGD
TABLE 2. Optical quality of the instruments in uUT-EGD compared with the previous SC-EGD
uUT-EGD (N Z 40)
uSC-EGD (N Z 40)
P value
Age, y*
56 G 13
54 G 12
.68
Age, y*
57 G 17
Sex, % female
45
38
.65
Sex, % female
40
Completed EGD, %
100
100
EGD procedure time, min *,y
5.2 G 0.7
4.9 G 0.8
.21
Endoscopist satisfaction score*,y
7.7 G 1.8
8.5 G 2.2
.88
Patient comfort score*,y
8.2 G 1.6
7.3 G 1.9
.78
Lower esophagus
7.5 G 2.1/7.3 G 2.0
.84
Antrum of the stomach
7.2 G 1.9/7.3 G 1.9
.77
Body of the stomach
6.5 G 2.0/7.3 G 1.9
.76
Duodenal bulb
7.7 G 2.1/7.2 G 2.2
.55
*Values represent mean and standard deviation. yScale 1-10, where 10 is excellent and 1 is poor; mean values of optical quality evaluated by 2 endoscopists are shown.
32 (80%)
12 (30%)
!.0001
25 (62%)
!.0001
Same
7 (17.5%)
Worse
1 (2.5%)
3 (7.5%)
.62
36 (90%)
33 (83%)
.52
Willing to repeat the same procedure
P value
Optical qualityy
Patient comfort in comparison with previous sC-EGD Better
uUT-EGD/SC-EGD (N Z 40)
*Values represent mean and standard deviation. yScale 1-10, where 10 is excellent and 1 is poor.
between the 2 groups. However, 80% (32/40) of patients who underwent uUT-EGD considered that the procedure was better than the previous uSC-EGD (vs 30% [12/40] of those who underwent a second uSC-EGD), suggesting that the use of a 5.2-mm–diameter videoscope may be superior to that of a 6.5-mm–diameter videoscope with regard to patient acceptance.
H pylori status was negative, whereas H pylori was positive in 24 of 29 (Endoscopist 1) or 30 (Endoscopist 2) RAC-negative patients. No false-positive findings were reported by either endoscopist. Based on the assessment of the 2 endoscopists, the overall sensitivity, specificity, PPV, NPV, and accuracy for the RAC pattern in recognizing H pylori–uninfected patients were 90%, 100%, 100%, 81%, and 93%, respectively (Table 4). The interobserver agreement for RAC was good (k Z 0.42).
DISCUSSION
In the 51 (Endoscopist 1) or 50 (Endoscopist 2) RAC– positive patients assessed by each of the 2 endoscopists,
Unsedated EGD has been shown to reduce the uncommon but substantial cardiopulmonary complications associated with sedated EGD.12-14 In addition, patients can return to work directly after the procedure and do not require a driver, resulting in a marked decrease in total costs associated with the procedure.6,14 However, most patients in the United States still find unsedated EGD when using these small-diameter instruments unacceptable, as evidenced by the up to 40% refusal rate of patients who were asked to participate in these studies.14 Endoscopists also prefer sedated EGD by using standard endoscopes to unsedated EGD when using small-diameter endoscopes.14 A 5.2-mm–diameter videoscope was developed with the goal of making unsedated EGD more acceptable. However, it is unclear whether small-diameter endoscopes produce a small but significant decrease in diagnostic accuracy and sensitivity.14 The specifications of the new videoscope are similar to conventional videoscopes, with the exception that it has only unidirectional up/down tip deflection. The study was conducted within the context that many Japanese undergo EGD at the same institution every year as part of a surveillance program to detect early gastric cancer. These results were based on the fact that
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Volume 64, No. 6 : 2006 GASTROINTESTINAL ENDOSCOPY 871
Study 2 The endoscopists’ evaluation of the optical quality of the instruments based on the ability to identify endoscopic finding is shown in Table 2. The mean score of optical quality assessed by 2 endoscopists was not significantly different between uUT-EGD and the previous sC-EGD. Although EGD findings, such as hiatal hernia, raised erosion, gastric submucosal tumor, and fundic glands polyp, were different between uUT-EGD and the previous sC-EGD, interobserver agreement for each endoscopic finding in uUT-EGD was perfect (k Z 1.0) between the 2 endoscopists (Table 3). The diagnostic accuracy of the uUT-EGD seemed to be similar to that of the previous sC-EGD.
Study 3
Unsedated ultrathin EGD
Horiuchi & Nakayama
TABLE 3. Endoscopic assessments by 2 independent endoscopists in uUT-EGD compared with the previous sC-EGD Endoscopist 1
Endoscopist 2
uUT-EGD/sC-EGD (N Z 40)
uUT-EGD/sC-EGD (N Z 40)
Kappa*
Esophageal SMT
1/1
1/1
1.0
Esophageal varices
1/1
1/1
1.0
Esophagitis
4/3
3/3
0.35
Hiatal hernia
5/8
5/8
1.0
RAC-positive
11/11
10/10
0.40
Raised erosion
3/2
3/2
1.0
GU scar
1/1
1/1
1.0
Gastric SMT
1/0
1/0
1.0
Fundic glands polyp
5/3
5/3
1.0
Gastric hyperplastic polyp
1/1
1/1
1.0
DU scar
1/1
1/1
1.0
Endoscopic features
SMT, Submucosal tumor; RAC, rearrangement of collecting venues; GU, gastric ulcer; DU, duodenal ulcer. *Interobserver agreement (Kappa statistics) on the presence or absence of each endoscopic finding in UT-EGD is shown.
most patients are able to remember the comfort levels of their previous EGDs; however, confirmation is needed when using a protocol where both studies are done at a closer interval. The 5.2-mm–diameter videoscope can be inserted perorally or transnasally.15 In a number of randomized controlled trials comparing transnasal with peroral unsedated EGD, peroral unsedated ultrathin EGD was the method preferred by both patients and endoscopists.16-18 In addition, the usefulness of unsedated esophagoscopy with a 4-mm–diameter endoscope was reported.19,20 However, the 4-mm–diameter endoscope did not suit EGD. In this study, all uUT-EGDs were performed perorally to allow direct comparison with the previous EGD. Eighty percent of the patients who underwent uUT-EGD considered the
procedure better than the previous uSC-EGD (vs 30% of those who underwent a second uSC-EGD), suggesting that the use of a 5.2-mm–diameter videoscope may be superior to the 6.5-mm–diameter videoscope with regard to patient acceptance. We attempted to evaluate the diagnostic accuracy of the 5.2-mm–diameter videoscope objectively by comparing the results (endoscopic photographs) of the uUT-EGD with those of the previous sC-EGD. We also used the RAC pattern, and the uUT-EGD was demonstrated to be essentially equivalent to the larger-diameter endoscope for the endoscopic detection of absence of H pylori infection (Tables 3 and 4). The data that the agreement was perfect (k Z 1.0) for 2 endoscopists reveal that the diagnostic accuracy of the 5.2-mm–diameter videoscope was within the acceptable range for detecting upper-GI diseases. Because tip deflection of the small-diameter endoscope is restricted to a unidirectional up-and-down motion, tip maneuverability requires rotation of the endoscope. This potential limitation did not prevent the endoscopist from obtaining a clear whole view at the upper GI (Table 2). The intensity of the light delivered and the airinsufflation ability from the small-diameter videoscope were not noticeably different from standard videoscopes. The results of the present study highlight the trade-offs between the potential benefits of unsedated EGD with slim endoscopes and the potential for a decrease in maneuverability and diagnostic accuracy associated with smallercaliber endoscopes. The data support the notion that adoption of this videoscope in primary care facilities in which the use of sedation is restricted should be encouraged.
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TABLE 4. Association of presence or absence of RAC with H pylori infection in uUT-EGD: comparison between 2 endoscopists RAC (C)/ H pylori (–)
Se (%)
Sp (%)
PPV (%)
NPV (%)
Accuracy (%)
Endoscopist 1
91
100
100
83
94
Endoscopist 2
89
100
100
80
93
Both endoscopists
90
100
100
81
93
RAC, Rearrangement of collecting venues; Se, sensitivity; Sp, specificity; PPV, positive predictive value; NPV, negative predictive value.
Horiuchi & Nakayama
ACKNOWLEDGMENTS We thank Masashi Kajiyama, Hideyasu Fujii, Hamako Hara, Chiemi Tanaka, and Satoko Takezawa for their dedicated technical assistance. As well, we wish to thank Torao Sakamoto (Showa Inan General Hospital) for his assistance with the statistical analysis. DISCLOSURE None of the authors work for Olympus Optical, receive support from the company, or have financial interest in the company.
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Unsedated ultrathin EGD 9. Nakayama Y, Horiuchi A, Kumagai T, et al. Discrimination of normal gastric mucosa from Helicobacter pylori gastritis using standard endoscopes and a single observation site: studies in children and young adults. Helicobacter 2004;9:95-9. 10. Kashiwagi H. Ulcers and gastritis. Endoscopy 2005;37:110-5. 11. Singer AJ, Thodes HC Jr. Determination of the minimally clinically significant difference on a patient visual analog satisfaction scale. Acad Emerg Med 1998;5:1007-11. 12. Lieberman DA, Wuerker CK, Katon RM. Cardiopulmonary risk of esophagogastroduodenoscopy: role of endoscope diameter and systemic sedation. Gastroenterology 1985;88:468-72. 13. Bell GD. Preparation, premedication, and surveillance. Endoscopy 2004;36:23-31. 14. Sorbi D, Chak A. Unsedated EGD. Gastrointest Endosc 2003;58:102-10. 15. Shaker R, Saeian K. Unsedated transnasal laryngo-esophagogastroduodenoscopy: an alternative to conventional endoscopy. Am J Med 2001;111(Suppl 8A):153S-6S. 16. Craig A, Hanlon J, Dent J, et al. A comparison of transnasal and transoral endoscopy with small-diameter endoscopes in unsedated patients. Gastrointest Endosc 1999;49:292-6. 17. Zaman A, Hahn M, Hapke R, et al. A randomized trial of peroral versus transnasal unsedated endoscopy using an ultrathin videoendoscope. Gastrointest Endosc 1999;49:279-84. 18. Wilkins T, Brewster A, Lammers J. Comparison of thin versus standard esophagogastroduodenoscopy. J Fam Pract 2002;51:625-9. 19. Catanzaro A, Faulx A, Isenberg GA, et al. Prospective evaluation of 4mm diameter endoscopes for esophagoscopy in sedated and unsedated patients. Gastrointest Endosc 2003;57:300-4. 20. Thota PN, Zuccaro G Jr, Vargo JJ 2nd, et al. A randomized prospective trial comparing unsedated esophagoscopy via transnasal and transoral routes using a 4-mm video endoscope with conventional endoscopy with sedation. Endoscopy 2005;37:559-65.
Received September 26, 2005. Accepted January 2, 2006. Current affiliations: Department of Gastroenterology (A.H.) and Pediatrics (Y.N.), Showa Inan General Hospital, Komagane, Japan. Reprint requests: Akira Horiuchi, MD, Department of Gastroenterology, Showa Inan General Hospital, 3230 Akaho, Komagane 399-4191, Japan.
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