Introduction
Introduction
Video capsule endoscopy (VCE) for diseases of the small intestine was introduced into
clinical practice in 2001. Over the past 8 years, an annually increasing number of
publications have shown that VCE is a reliable, noninvasive method for endoscopic
examination of the entire small-bowel mucosa. An esophageal [2] and a colon capsule [3] have also been launched on the market and are under intensive clinical investigation.
The aim is to update the previous document published over 3 years ago, in 2006 [4]. The updated recommendations are presented in [Table 2].
Table 1 Categories of evidence and grades of recommendation (adapted from reference [1]).
| Grade of recommendation |
Categories of evidence |
|
Types of study |
| A |
1 |
1a |
Systematic review of randomized controlled trials of good methodological quality and
with homogeneity |
|
|
1b |
At least one randomized controlled trial with narrow confidence interval |
| B |
2 |
2a |
At least one well designed controlled study without randomization |
|
|
2b |
Noncontrolled cohort studies |
|
3 |
3a |
Systematic review of case–control studies (with homogeneity) |
|
|
3b |
Individual case–control study |
| C |
4 |
4 |
Case series/poor quality cohort or case controlled studies |
| D |
5 |
5 |
Expert committee reports or opinions, or clinical experiences of respected authorities
|
Table 2 The 2009 European Society of Gastrointestinal Endoscopy (ESGE) updated information
for video capsule endoscopy (VCE).
| Statements |
Category of evidence |
Grade of recommendation |
|
Small-bowel preparation
|
|
|
| Purgative bowel preparation enhances the diagnostic yield of small-bowel VCE [5], but does not affect VCE completion rate [6]
[7]
[8]
|
2a |
B |
|
Obscure gastrointestinal bleeding
|
|
|
| VCE is the first-line examination in obscure gastrointestinal bleeding (OGIB) after
a negative upper and lower gastrointestinal endoscopy [9]
[10]
[11]
[12]
[13]
[14]
[15]
[16]
[17]
[18]
[19]
[20]
[21]
|
2b |
B |
| Patients with unexplained iron-deficiency anemia should undergo small-bowel VCE examination
[22]
|
2b |
B |
|
Crohn’s disease
|
|
|
| VCE is the best procedure to evaluate small-bowel mucosal lesions in Crohn’s disease
[23]
|
3a |
B |
| The risk for capsule retention in suspected or established Crohn’s disease is high.
Small-bowel imaging or patency capsule should precede VCE [24]
[25]
|
2b |
B |
| Nonsteroidal anti-inflammatory drugs (NSAIDs) should be stopped 2 months prior to
VCE [26]
|
2a |
B |
|
Celiac disease
|
|
|
| VCE has a high diagnostic yield in patients with suspected celiac disease [27]
[28]
[29]
|
2b |
B |
| Patients with refractory or complicated (jejunoileitis, intestinal lymphoma) celiac
disease should have a VCE examination [30]
[31]
|
2b |
B |
|
Polyposis syndromes and small-bowel tumors
|
|
|
| VCE should be considered to be a first-line screening modality for surveillance in
patients with Peutz–Jeghers syndrome [32]
[33]
[34]
[35]
|
2b |
B |
| VCE examination of the small bowel is indicated in familial adenomatous polyps (FAP)
patients with duodenal polyps [36]
[37]
[38]
|
2b |
B |
| VCE examination influences the therapeutic work-up of small-bowel tumors [39]
[40]
|
3b |
B |
|
Esophageal VCE
|
|
|
| VCE has good agreement with conventional esophagogastroduodenoscopy (EGD) in diagnosing
Barrett’s esophagus and esophageal varices [41]
[42]
[43]
|
2a |
B |
Video capsule system
Video capsule system
The VCE system consists of: (i) a capsule containing the video camera; (ii) a sensing
system comprising an array of sensor pads, a data recorder, and a battery pack; and
(iii) a workstation, based on a commercially available personal computer. There is
also a portable external viewer for directly monitoring the images received during
the examination.
In the last 3 years there have been several technological advances, both in the capsule
itself and the associated hardware and software, that have greatly improved image
quality and battery lifespan. Currently, capsule endoscopy systems are manufactured
by four companies.
Given Imaging Ltd (Israel) first delivered wireless capsule endoscopy in 2001. Today,
capsule endoscopy devices from Given Imaging include the PillCam SB for the small
intestine, the PillCam ESO for esophageal imaging and Pillcam Colon for the large
bowel. More recently, Olympus (Japan) have produced the EndoCapsule for the small
bowel; IntroMedic (Korea) have developed the MiRoCam for small-bowel evaluation using
electric-field propagation for data transmission [44], and, finally, the Chongqing Jinshan Science and Technology Group (China) have launched
the OMOM small-bowel capsule.
Whilst the PillCam captures images using a complementary metal oxide silicon (CMOS)
sensor, the EndoCapsule, MiroCam, and OMOM capsule use a charge-coupled device (CCD).
The four capsules also differ with regard to dimensions, image acquisition frame rate,
field of view, and recording duration ([Table 3]).
Almost all of the information provided in this document is based on published data
regarding the Given Imaging PillCams. Data concerning the EndoCapsule are scarce in
the literature [45]
[46]
[47], and there is even less concerning the other two systems [5]
[44]
[48].
Table 3 Technical specifications of small-bowel capsules.
|
Pillcam SB2 |
EndoCapsule |
MiroCam |
OMOM capsule |
| Length, mm |
26 |
26 |
24 |
27.9 |
| Diameter, mm |
11 |
11 |
11 |
13 |
| Weight, g |
3.4 |
3.8 |
3.4 |
6 |
| Frame rate, frames/second |
2 |
2 |
3 |
0.5–2 |
| Image sensor |
CMOS |
CCD |
CCD |
CCD |
| Field of view |
156° |
145° |
150° |
140° |
| Illumination |
6 white LEDs |
6 white LEDs |
6 white LEDs |
NA |
| Antennas (body leads), n |
8 |
8 |
9 |
14 |
| Real-time (RT) view |
RT viewer |
VE-1 viewer |
Miro-Viewer |
RT monitoring |
| Recording time, hours |
8 |
9 |
11 |
7 – 9 |
| CMOS, complementary metal oxide semiconductor; CCD, charge-coupled device; LED, light-emitting
diode; NA, not applicable |
Patency capsule
Patency capsule
The patency system of Given Imaging (Yoqneam, Israel) consists of: (i) a self-disintegrating
capsule (the AGILE capsule), without a camera but containing a radiofrequency identification
(RFID) tag; and (ii) a RFID scanner. The AGILE capsule, which replaced the M2A patency
capsule, is identical in size to the small-bowel PillCam (26 mm long, 11 mm wide).
This solid, biodegradable capsule contains the small RFID tag (2 × 12 mm) within a
radio-opaque lactose and barium body. This body is coated with an impermeable membrane
of parylene except for two small windows; these allow luminal fluid access to paraffin
timer plugs to bring about disintegration of the capsule within 30 hours [49]
[50]. The capsule remnants can pass through even small orifices. The RFID tag within
the capsule transmits signals that are detected by the RFID scanner. Detection of
a radiofrequency signal by the scanner indicates that the capsule is still in the
gastrointestinal tract. The radio-opaque capsule can be detected by plain abdominal
X-ray.
The AGILE capsule has been shown to provide evidence of the functional patency of
the gastrointestinal tract in patients with known or suspected intestinal stricture
[49]. Functional patency is verified by this test if the AGILE capsule is egested intact
without any change in its original dimensions, irrespective of the time of expulsion,
or, if the RFID tag is not detected when the patient is scanned at 32 – 38 hours.
Patients at high risk who develop pain during the AGILE capsule test are not eligible
for VCE examination [49].
Small-bowel video capsule endoscopy (VCE)
Small-bowel video capsule endoscopy (VCE)
Small-bowel preparation
The preparation for VCE suggested by manufacturers of capsule endoscopy systems consists
only of a clear liquids diet and an 8-hour fast. However, two factors that impair
the diagnostic yield of VCE are first, the presence of food residue, air bubbles and
turbid or green viscous intraluminal fluid, and secondly failure of the capsule to
visualize all of the small-bowel due to delayed gastric or small-bowel transit times.
In some studies therefore purgatives have been used, to clean the small-bowel mucosa,
but results have been inconclusive. A recent meta-analysis has shown that small-bowel
purgative preparation (polyethylene glycol solution or sodium phosphate) improves
the diagnostic yield of the examination [6]. It also showed better quality of visualization of the mucosa in patients receiving
purgatives, but there was significant heterogeneity between the nine sets of data.
The meta-analysis did not detect any difference between purgative preparation and
clear liquids diet regarding VCE completion rate, VCE gastric transit time (GTT),
and VCE small-bowel transit time (SBTT) [6].
Another meta-analysis and a systematic review that examined the effectiveness of bowel
preparation for VCE also included studies using prokinetics and simethicone (in contrast
to the previous study). The first one (on seven studies) did not address the important
issue of VCE diagnostic yield [7]. The second (on 14 studies), published in abstract form, showed that bowel preparation
had no effect on VCE diagnostic yield [8]. However, both studies [7]
[8] are in agreement with Rokkas et al. [6], regarding the effects of bowel preparation on the quality of mucosal visualization,
on VCE transit times, and on the completion rate of the examination.
While there is evidence for a benefit from bowel preparation for VCE, there is so
far no consensus on the preparation regimen. Several investigators favor half-doses
of purgatives in the evening before the examination, others prefer a colonoscopy-like
preparation while some advocate administration of the preparation even during the
examination [51]
[52]. In a well-designed randomized controlled trial, the administration of simethicone
in order to reduce air bubbles has been shown to improve visibility of the mucosa
of at least the proximal part of the small bowel during VCE recording [53]. Nevertheless, the 2006/2007 consensus statements for small-bowel capsule endoscopy
[54] did not report consistent clinical benefit for these agents.
Although adverse events and patient intolerance might be associated with the use of
bowel purge for VCE, as inferred from colonoscopy studies, these have not yet been
reported [54]. Moreover, the largest published meta-analysis on bowel preparation for VCE [6] has not detected clinically significant adverse events related to bowel preparation.
In conclusion, small-bowel preparation before VCE seems to improve the visibility
of the small-bowel mucosa, without any difference in terms of VCE completion rate
or capsule GTT and SBTT. The data from the meta-analysis also show that small-bowel
preparation improves the diagnostic yield of VCE [6].
VCE completion rate
Small-bowel VCE completion rate is about 80 % [6]. Retrospective studies have identified factors such as inpatient status [55]
[56], previous abdominal surgery [56], poor bowel cleansing [56] and prolonged GTT [56] that may predict incomplete small-bowel VCE examination, while the effects of diabetes
mellitus [55]
[57] and of greater age are controversial [55]
[58]. Patients at increased risk for incomplete examination might benefit from the use
of the real-time viewer periprocedurally and then intervention with endoscopic placement
of the capsule in the duodenum [56]
[59]. There has been promising use of the real-time viewer to optimize the timing of
bowel preparation, thus improving its quality [52], but this has not been studied extensively yet.
Indications
Indications
Obscure gastrointestinal bleeding
Obscure gastrointestinal bleeding (OGIB) is the most frequent indication for small-bowel
VCE examination. The yield of VCE in patients with OGIB is significantly higher for
patients with ongoing overt bleeding compared with patients with obscure occult bleeding.
The diagnostic yield is also higher when the examination is performed within 48 hours
of patient hospitalization for the bleeding episode [9].
The rate of rebleeding in patients with OGIB and negative VCE is significantly lower
(4.6 %) compared with those with a positive VCE (48 %) [10].
A large retrospective survey from the Mayo Clinic showed that the yield of VCE in
the obscure-overt group (60 %) was significantly higher than in the obscure-occult
group (46 %). For the OGIB patients overall, after VCE there was significant reduction
in hospitalizations, additional investigations, and units of blood transfused compared
with before VCE [11].
Several prospective studies and a meta analysis [12] have compared VCE with push enteroscopy in the evaluation of patients with OGIB.
They have shown a significantly better yield for VCE (63 %) compared with push enteroscopy
(23 %). In a recent randomized study, VCE and push-enteroscopy were used for first-line
exploration of OGIB and identified a bleeding source in 50 % vs. 24 %, of patients,
respectively (P = 0.02) [13]. Furthermore, in another study, it was shown that VCE detected a source of bleeding
in a greater proportion of patients (72 %), than computed tomography (CT) angiography
(24 %), or standard angiography (56 %) and gave positive findings in more than half
of the cases that were negative at computed tomography or angiography [14]. When compared with intraoperative endoscopy as reference, VCE had sensitivity,
specificity and positive and negative predictive values of 95 %, 75 %, 95 %, and 86 %
respectively [15].
Studies published to date have shown that the diagnostic yield for VCE is higher compared
with that of double-balloon enteroscopy (DBE) [16]
[17]
[18]. In a US multicenter trial, the agreement between VCE and DBE was about 74 % for
angioectasias, 96 % for ulcerations, 94 % for mucosal and submucosal polyps, and 96 %
for large tumors [19]. Two studies investigated the yield and the outcomes of DBE following VCE in patients
with OGIB. Patients first underwent VCE and then DBE. The overall detection rates
for both techniques were similar. Therefore, these two techniques may be considered
complementary [20]
[21]. However, DBE may permit endoscopic treatment of the bleeding lesion [21].
VCE is a cost-effective investigation in patients with OGIB. The diagnostic yield
of VCE compared with other imaging procedures has been evaluated as a measure of efficacy.
The mean cost of a positive diagnosis with VCE was 2091 € and that of other procedures
was 3829 € with a mean cost saving of 1738 € for one positive diagnosis [21].
Iron-deficiency anemia
VCE is a useful examination for investigating potential small-bowel causes of iron
deficiency anemia (IDA). A study recruited 51 patients to undergo capsule endoscopy
for unexplained IDA following a negative work-up and exclusion of other causes of
anemia. Capsule endoscopy identified a likely source of IDA in 57 %, while enteroclysis
revealed abnormal findings likely to be causing IDA in only 11.8 % of the patients
(P < 0.0001) [22].
Nonstricturing small-bowel Crohn’s disease
VCE has a high diagnostic yield for small-bowel lesions of Crohn’s disease in patients
with suspected as well as established disease. The main reasons for a VCE procedure
in Crohn’s disease are to establish the diagnosis, to assess disease prognosis, disease
activity, and mucosal healing post therapy, and to define the extent and severity
of disease. VCE examination may be particularly important before medication dosage
is changed, and for follow-up after immunomodulators and biologics have been given.
VCE may permit confirmation of the diagnosis when Crohn’s disease is suspected on
clinical grounds, without a definite diagnosis from another modality.
A recent meta-analysis summarized the diagnostic yield of VCE for this disease in
comparison with all the other available procedures [23]. For all the patients examined, significant incremental diagnostic yields were found
as follows: small-bowel follow-through 40 % (9 studies); colonoscopy and ileoscopy
15 % (4 studies); CT enterography 38 % (3 studies); push enteroscopy 38 % (2 studies);
and magnetic resonance imaging (MRI) 22 % (1 study) [23]. There was no significant difference seen between VCE and alternate modalities for
diagnosing small-bowel Crohn’s disease in patients with a suspected initial presentation,
but a trend towards significance suggests the possibility of type II error. Subgroup
analysis of patients with established disease and suspected small-bowel recurrence
revealed a statistically significant difference in diagnostic yield in favor of VCE
compared with all the modalities mentioned. In a small prospective study in known
or suspected Crohn’s disease, the sensitivity of VCE for active small-bowel Crohn’s
disease was not significantly different from computed tomography, ileocolonoscopy
or even small-bowel follow-through [60]. However, it was concluded that lower specificity and the need for preceding radiography
due to the high frequency of retention may limit its use as a first-line test. VCE
was found to be more effective than colonoscopy and intubation of the neoileum after
surgery for Crohn’s disease [61]. Out of 24 patients prospectively studied, recurrence was demonstrated in 15 (62 %)
with the VCE and only in 6 (25 %) with colonoscopy. VCE should also be considered
in ulcerative colitis patients with atypical clinical features, particularly after
colectomy and in cases of indeterminate colitis [62].
The risk for VCE retention in Crohn’s disease patients is estimated to be 5 % – 13 %
[24]. Thus, small-bowel follow-through, CT, or patency capsule examinations that exclude
stricture should be performed first in suspected or established Crohn’s disease [25].
Not all ulcers are Crohn’s disease, and not all biopsies are confirmatory. Nonsteroidal
anti-inflammatory drug intake, lymphoid hyperplasia, lymphoma, radiation enteritis,
vasculitis, or infectious disease may cause similar lesions in the small bowel. Nonsteroidal
anti-inflammatory drugs should be stopped 2 months prior to the test [26]. To overcome some of these obstacles a diagnostic index has been developed with
a scoring system that enables estimation of small-bowel disease activity for clinical
and investigational needs [63].
The importance of mucosal healing is now under intense scrutiny in the era of new
investigational therapy for Crohn’s disease. VCE is the only method, except for double-balloon
enteroscopy, for accurate assessment of mucosal healing. However a prospective study
comparing clinical response to therapy and evidence for mucosal healing as found at
VCE could not establish a significant correlation between them [64]. Recently, the advent of double-balloon enteroscopy has provided a ”gold-standard”
modality for assessing the diagnostic yield of VCE. Outcome studies with a long follow-up
after VCE procedures are still needed. A small, prospective study of 27 patients suspected
to have Crohn’s disease, revealed a sensitivity of 93 % and specificity of 84 % for
the VCE examination, and demonstrated a significant change in their management [65].
Celiac disease
VCE may be a useful tool for the diagnosis of celiac disease, because it is noninvasive,
it images the entire length of the small bowel and is able to detect minute mucosal
details including changes in intestinal villi.
Suspected celiac disease. Two studies in patients with suspected celiac disease and positive celiac serology
[27]
[28] compared the diagnostic performance of VCE with that of conventional upper gastrointestinal
endoscopy with duodenal biopsies. Using duodenal histology as the gold standard, both
studies showed that VCE had good sensitivity (85.0 % – 87.5 %) and specificity (100 % – 90.9 %)
for the diagnosis of celiac disease. In a more recent study [29] carried out in untreated patients with biopsy-proven celiac disease, VCE had 92 %
sensitivity and 100 % specificity for the detection of villous atrophy.
Refractory or complicated celiac disease. In a study of 47 patients with complicated celiac disease [30], VCE had a high diagnostic yield, by identifying mucosal abnormalities and by excluding
adenocarcinoma. In another study of 14 patients with refractory celiac disease [31], VCE identified signs of ulcerative jejunoileitis or intestinal T-cell lymphoma
in 2/7 patients with type II refractory celiac disease. In one of these, the diagnosis
could be made by VCE only.
Hereditary polyposis syndromes
A small series showed that VCE is more effective than barium contrast studies in detecting
small-bowel polyps in patients with familial adenomatous polyposis (FAP) or Peutz–Jeghers
syndrome (PJS) [32]. Its accuracy has been shown to equal to that of MRI for detecting small-bowel polyps
bigger than 15 mm, but the detection rate for polyps 5 – 15 mm in size was much higher
for VCE and polyps smaller of 5 mm were visualized only by VCE; however, it provided
only partial views of large polyps, while MRI provide a better estimation of the site
and the size of the detected polyps [33]. Available published data suggest that now VCE may replace enteroclysis for surveillance
in PJS patients [34]
[35].
VCE is indicated in FAP patients with duodenal polyps, because these patients may
develop small-bowel polyps [34]
[35]
[36]. Although VCE allows better visualization of the small bowel than other noninvasive
diagnostic methods, it has low sensitivity for identifying the major papilla and does
not seem accurate in distinguishing the ampullary from the periampullary region [35]
[36]
[37]
[38]. Therefore, the use of side-view duodenoscopy for staging duodenal disease is mandatory.
Few comparative data are available for VCE versus enteroscopy in the setting of FAP
[66].
Small-bowel tumors
Following the introduction of VCE in clinical practice, it was shown that the frequency
of small-bowel tumors is higher than previously published (2 %), ranging from 2.4 %
to 9.6 % in patients who underwent VCE for a variety of indications [39]
[40]
[67]
[68]
[69]
[70]
[71]. In patients with small-bowel tumors the usual clinical indication for VCE examination
is obscure gastrointestinal bleeding (OGIB) in about 70 % – 90 % of cases [39]
[40]
[67]
[68].
The majority of tumors identified by VCE are adenocarcinomas, followed by carcinoids,
lymphomas, sarcomas and hamartomas [39]
[67]
[68]
[70]. Gastrointestinal stromal tumors (GISTs) are the most frequent benign neoplasm,
accounting for about 32 % of all cases [40]. Other benign neoplasms include inflammatory polyps, lymphangiomas, lymphangioectasias,
hemangiomas, hamartomas, adenomas, and lipomas. Melanoma is the most common tumor
metastasizing to the small bowel [72], but metastases derived from colorectal cancer and hepatocellular carcinoma have
also been reported [40]
[68]
[71]. Tumors are located in the jejunum (40 % – 60 %), the ileum (25 % – 40 %), and less
frequently in the duodenum (15 % – 20 %).
The diagnosis of small-bowel tumors has often been delayed when traditional techniques
are used. The majority of patients with small-bowel tumors usually undergo multiple
investigations prior to VCE without any definitive diagnosis. The average work-up
prior to VCE has been reported to range between 3.6 and 5 previous negative procedures
per patient [39]
[69]
[71]. VCE provides a satisfactory estimation of tumor location compared with surgery
or autopsy [40]
[71] and it seems to influence the therapeutic work-up, providing information on the
location, dimension, and appearance of the lesion [39]
[40].
Limitations and risks
Limitations and risks
Small-bowel VCE has a few limitations and risks, of which those practicing VCE examination
should be aware. MRI examination, if needed, should not be done before the capsule
is expelled from the gastrointestinal tract. VCE should also not be used in patients
with swallowing disorders, due to the risk of aspiration. Pregnancy is regarded as
a contraindication for VCE examination because of the microwaves transmitted by the
capsule. However, there are two case reports of VCE examination during the first trimester
of pregnancy [73]
[74]. Capsule retention in the stomach and known or suspected small-bowel strictures
are discussed in other sections. VCE is not contraindicated in patients with a cardiac
pacemaker [75] or implantable cardiac defibrillator [76] and there is no interference between the two devices.
Esophageal video capsule endoscopy
Esophageal video capsule endoscopy
In 2004, Given Imaging developed an esophageal video capsule (PillCam ESO) as a noninvasive
device for the examination of the esophagus. The capsule was similar in size as the
intestinal capsule, but was equipped with two optical domes, allowing the capture
of 14 images/second, 7 from each side [2]. The operating time was 20 minutes. A new version was released by Given Imaging
in 2007, the PillCam ESO 2 [77], with an almost doubled field-of-view, a 50 % increase in depth-of-view, a frame
rate of 15 frames/second, better image quality and a wide dynamic range, and illumination
adjusted in real time to provide optimal images. A specific ingestion protocol is
required to slow down the transit of the capsule along the esophagus and increase
the duration of examination of the esophageal mucosa. The patient lies on their right
side and following ingestion of the capsule swallows sips of water every 15 seconds
over 3 minutes [78].
The main indications for esophageal VCE are screening of Barrett’s esophagus and of
esophageal varices. Since 2006, the accuracy of esophageal VCE for detecting lesions
related to gastroesophageal reflux has been evaluated in several studies comparing
the diagnostic yield of VCE and esophagogastroduodenoscopy (EGD) [41]
[42]
[79]
[80]. In these studies, esophageal VCE appeared feasible, safe, well tolerated, and always
preferred by patients to unsedated EGD. However, the sensitivity of esophageal VCE
was quite variable between studies, ranging from 60 % to 100 % for Barrett’s esophagus
and from 50 % to 89 % for erosive esophagitis. In addition, in a recent study, a quite
low diagnostic agreement was found between esophageal VCE and EGD in a heterogeneous
series of patients undergoing EGD because of suspicion of various esophageal diseases
[43].
A large, multicenter prospective study compared EGD and esophageal VCE for the detection
of esophageal varices [81], and showed very good positive and negative predictive values (92 % and 77 %, respectively)
and an overall fair agreement with EGD (kappa 0.73). Moreover, in discriminating between
medium/large varices requiring treatment and small/absent varices requiring surveillance,
the positive and negative predictive values for VCE were 87 % and 92 %, respectively,
with a substantial overall agreement of 91 % (kappa 0.77) on treatment decisions based
on variceal size. Two recent studies have compared the cost-effectiveness of esophageal
VCE versus EGD and/or systematic prescription of prophylaxis by beta-blocking agents
[82]
[83]. None of these studies demonstrated superiority of esophageal VCE over the other
approaches.
Both in the screening of Barrett’s esophagus and of esophageal varices, the usefulness
of esophageal VCE must be weighed against the wide availability of EGD, its good tolerability
and relatively low cost. Moreover, EGD allows a complete examination of the stomach
and duodenum during the same procedure and biopsy sampling.
Video capsule endoscopy of the colon
Video capsule endoscopy of the colon
The PillCam Colon capsule (Given Imaging) has recently been launched on the market.
The device has some technical differences from the small-bowel capsule: it is approximately
6 mm longer; it has dual cameras that enable the device to acquire video images from
both ends, optics with more than twice the coverage area of the small-bowel capsule;
automatic light control; and a frame rate of four frames per second. After initial
capsule activation and 5 minutes of image transmission, the capsule enters a delay
mode of approximately 2 hours, after which it spontaneously ”wakes up” and restarts
the transmission of images for approximately 10 hours. [3]
[84]. The recommended preparation regimen consists of conventional colonoscopy preparation
plus ingestion of domperidone before capsule ingestion, and boosts of sodium phosphate
purge and bisacodyl suppositories during the examination [3]
[84]
[85].
This noninvasive examination has been evaluated in two pilot studies [3]
[84], in one large European trial [85], and in a meta-analysis [86] as an alternative modality for colon neoplasia screening. Data from these studies
suggest that the colon capsule is expelled within 10 hours post ingestion in from
74 % of patients [3] to more than 90 % [85], allowing therefore the examination of the entire colon in the majority of patients.
However, bowel cleansing is an issue. In the two pilot studies there was poor bowel
preparation in 1 % – 3 % of cases [3]
[84], but in the large European trial the proportion of cases with fair/poor bowel preparation
was 29 % [85]. No examination-related adverse events have been reported to date [3]
[84]
[85]. According to the meta-analysis [86], the sensitivity and specificity of colon VCE for the detection of significant colon
adenomas and carcinomas are 69 % and 86 %, respectively, suggesting that although
it is a promising tool, colon VCE needs improvement before it can be an alternative
to colonoscopy for colon cancer screening.
Colon VCE might also have potential first as a complement to incomplete colonoscopy,
and secondly where conventional colonoscopy is either refused by patients or poses
substantial risk to them. A small case series did not show encouraging results for
the first proposition [87], and there are no published data regarding the second.
Competing interests: None
