Chromoendoscopy Plus Mucosal Resection Versus Conventional Electrocoagulation for Intestinal Polyps in Children: Two Case Series

Abstract

Background:

Conventional high-frequency electrocoagulation (HFEC) of intestinal polyps may be difficult in children and endoscopic mucosal resection (EMR) could be a less invasive option. Chromoendoscopy improves tissue localization during endoscopy, but its exact influence on the outcomes of children with intestinal lesions is still unknown.

Aims:

To analyze a series of children treated with EMR or HFEC and assess the value of chromoendoscopy.

Methods:

This was a retrospective analysis of two case series of patients treated at the Gastroenterology Department of the Guiyang Children's Hospital between February 2014 and November 2016. The children underwent EMR (n = 34) or conventional HFEC (n = 120). Demographic, clinical, and perioperative data were analyzed.

Results:

The polyps were larger in the HFEC group [median, 3.9 (0.1–27.0) versus 1.3 (0.03–64.0) mm, P = .03]. There was a higher frequency of multiple polyps in the EMR group (50.0% versus 15.1%, P < .001). Operation time and intraoperative bleeding were similar between the two groups (both P > .05). Hospital stay was longer with EMR than with HFEC [median, 5 (3–12) versus 4 (2–14) days, P = .02]. There was no intestinal perforation in either group. Postoperative bleeding amount was similar in both groups (P = .73). In the EMR group, 19 patients were operated using chromoendoscopy, whereas only 2 patients in the HFEC group were operated.

Conclusion:

EMR could be appropriate for the treatment of intestinal polyps in children.

Introduction

Colonic polyps are the major cause of lower gastrointestinal hemorrhage in children. Most polyps in children are in the rectum and the peak incidence is between 2 and 10 years of age (85%).^1,2 Rectal bleeding is the presenting symptom in most children (75%) and the polyps are usually solitary (94%), juvenile (86%), and located in the rectosigmoid area (87%).^1,2 With the increasing application of colonoscopy in children, the detection of multiple colorectal polyps, early micropolyps, flat wide-base polyps, and polyps at special parts is increasing in children.^1–3 Malignant changes of colorectal polyps in children have also been reported.^1,4 Polyps in children may have a familial component.^5,6

Because of their malignant potential, all polyps in children must be removed.^1,4 Colonoscopic high-frequency electrocoagulation (HFEC) is the main treatment method.^1,4,7 Nevertheless, there are several disadvantages to conventional snaring-electrocoagulation of polyps in children. For instance, flat wide-based sessile polyps close to the anus are very difficult to snare. In addition, it is easy to snare too much intestinal tissues during conventional snaring-electrocoagulation, increasing the risk of perforation. It is also difficult to obtain complete biopsies when using conventional electrocoagulation for micropolyps. A surgical resection may have to be considered in these cases, but it is invasive.⁸

Intestinal polyps in adults may be resected using endoscopic mucosal resection (EMR), which includes submucosal injection-assisted EMR, cap-assisted EMR (EMRC), and endoscopic piecemeal mucosal resection (EPMR).^9–11 Because of the differences in the size of the anatomic structures, techniques for adults cannot always be used directly in children. Chromoendoscopy is the use of staining to improve tissue localization, characterization, and diagnosis during endoscopy, and it is safe, inexpensive, and quick.^12,13 In contrast, the interpretation of the findings is not always easy. In addition, its exact influence on the outcomes of patients with intestinal lesions is still unknown.^14,15

Considering the need for removing colorectal polyps in children, the present study aimed to analyze our series of children treated with EMR between February 2014 and April 2016, and assess the value of chromoendoscopy. The results could help shedding some light on the appropriate management of these patients.

Materials and Methods

Study design and patients

This was a retrospective analysis of patients treated at the Gastroenterology Department of the Guiyang Children's Hospital between February 2014 and November 2016. All included children were confirmed with colonic polyps by colonoscopic examinations. The study was approved by the Ethics Committee of the Guiyang Children's Hospital. The need for individual consent was waived by the committee because of the retrospective nature of the study.

The inclusion criteria were (1) <14 years of age, (2) diagnosis of intestinal polyps,^1–3 and (3) surgical treatments. For most children, the families were asked to sign the informed treatment consent after the endoscopic examinations, and surgery was completed during the endoscopic examination. As these were child patients, such procedures could benefit the children and their families by simplifying the procedures and reducing the number of bowel preparations and pain from repeated operations. In addition, some tiny lesions may not be easy to be found again during re-examination.

The indications for endoscopy were (1) symptoms and signs such as hematochezia, abdominal pain, stool changes, history of intestinal polyps, and family history; or (2) transferred from other regional hospitals for hematochezia and other symptoms, and suspected with colonic polyps that needed colonoscopic examinations.

The exclusion criteria were (1) Peutz-Jeghers syndrome, (2) malignant tumor or hematological diseases, or (3) coagulation disorders.

Treatments and grouping

The polyps were classified according to the Yamada classification.¹⁶ The children with Yamada type I polyps, most children with Yamada type II polyps, and some children with Yamada type III polyps underwent EMR. Children with giant wide-base polyps underwent EPMR. Children with Yamada type II polyps close to the anus underwent EMRC. All the other children with polyps during the same time period were included as controls and underwent routine HFEC.

Endoscopic mucosal resection

EMR was performed using a PEF-Q180AI electronic colonoscope, PSD-30 high frequency generator, SD-5 U/6 U-1 electronic snare, NM-400 L-0423 syringe, HX-110UR titanium clip releaser (if needed), HX-610-135 titanium clip (if needed), and MH-593 transparent cap (all from Olympus, Tokyo, Japan). Normal saline was used for the submucosal injection.

For mucosal staining, the indigo carmine mucosal staining agent (Nanjing Technology Co., Ltd., Nanjing, China; #MTN-DYZ-15; concentration: 0.2% ± 0.05%) was used for staining the colonic mucosa through an endoscopic spraying tube (WP-18/1800; Nanjing Technology Co., Ltd.). The patients with polyps confirmed by colonoscopy were scheduled for HFEC or EMR. The mucosal staining agent was routinely sprayed to the intestinal segments with polyps, sigmoid colon, and high-risk areas of the rectum to fully display the outline of the polyps and the border between the base and pedicle, which could help in determining the site for submucosal injection. In addition, these procedures could also fully display the small polyps that could not be clearly displayed, or easy to be missed by conventional colonoscopy, and thus reduce the rate of misdiagnosis.

For submucosal injection-assisted EMR, the visual field was fully exposed to observe the location, size, shape, and base of the polyps. For the submucosal injection, the needle of the syringe was inserted at 2 mm to the margin of the lesion toward the center of the lesion, and saline was injected to the submucosal layer to form a “saline cushion” to lift the lesion sufficiently from the muscular layer. Then, 2–10 mL of normal saline was injected until the surrounding mucosa showed the lifting sign. No multipoint injection was conducted. The lesion was successfully snared, and the polyps were completely removed for pathological examinations.

For the children in whom the lesion was not easy to snare, EMRC was conducted. Distal-end transparent cap matching the colonoscope was selected and fixed to the leading end of the colonoscope. Two methods of cap assistance could be used. First, the snare was placed in the transparent cap. After the colonoscope was delivered to the lesion area, the front end of the cap was aimed at the lesion center. Then, appropriate negative pressure was applied to suck the lesion into the cap, after which the snare was tightened for the snaring of the lesion. The other method was that after approaching the lesion with a colonoscope equipped with a transparent cap, the space between the cap and the lesion (or use the cap to push aside the polyps and intestinal folds to form a space) was used to deliver the snare, and then snaring was conducted. The first method was rarely used as the intestinal wall of children is relatively thin and the polyps are generally small, thus the negative pressure snaring could easily snare too much intestinal tissues, and the operators could not be sure whether the muscular layer was also snared or not. Since the second method uses the space between the polyps and colonoscope generated by the cap, the operation could be conducted under visual conditions, which not only facilitated snaring but also ensured the safety of electrocoagulation. The second method was used in this study to remove the polyps at the pectinate line close to the anus.

For Yamada type II polyps >20 mm and with a relatively wide base (about 15 mm), EPMR was applied. The first resection of the EPMR was started from the position relatively hard to be resected, and the second tissue to be resected was adjacent to the margin of the first resection to avoid residual lesion. When the bulge of the residual lesion was not sufficient, submucosal injection of 0.01% adrenalin saline could be conducted again.

The amount of intraoperative bleeding was grossly estimated by the surgeon by direct observation.

Postoperative management

The tissues resected were sent for pathological examinations. The children were hospitalized. The children were asked to avoid intense activities. Liquid diet was provided for 3 days, and the children were ensured to keep their bowels open. In addition, the clinicians were very careful to identify any delayed bleeding, perforation, and abdominal distension. The stools were examined for fecal blood during hospitalization.

Data collection

Demographic (gender and age), clinical (symptoms, polyp size, number, and location), and perioperative (operation time, bleeding, hospital stay, and adverse events) data were extracted from the medical charts.

Statistical analysis

Continuous data were tested for normal distribution using the Kolmogorov–Smirnov test. Normally distributed data were expressed as mean ± standard deviation and analyzed using the Student t test. Non-normally distributed data were presented as median (range) and analyzed using the Wilcoxon test. Categorical data were presented as frequencies and analyzed using the Fisher exact test. SPSS 16.0 (IBM, Armonk, NY) was used for analysis. Two-sided P-values <.05 were considered statistically significant.

Results

Characteristics of the patients

Table 1 presents the characteristics of the patients. There were no differences in gender, age, and duration of symptoms between the two groups. The polyps were larger in the electrocoagulation group (n = 120) [median, 3.9 (0.1–27.0) versus 1.3 (0.03–64.0) mm, P = .03] than in the EMR group (n = 34). There was a higher frequency of multiple polyps in the EMR group (50.0% versus 15.1%, P < .001).

Table 1.

Baseline Characteristics of the Patients

	EMR (N = 34)	Electrocoagulation (N = 120)	P value
Gender			.735
Male	26 (76.5%)	95 (79.2%)
Female	8 (23.5%)	25 (20.8%)
Age (months)	60 (24–150)	48 (12–168)	.399
Duration of symptoms (months)	6 (0.5–60)	6 (0.5–72)	.405
Size of the polyps (mm)	1.25 (0.03–64.00)	3.94 (0.13–27.00)	.032
Location of the polyps			—
Ascending colon	1 (2.9%)	0
Transverse colon	9 (26.5%)	6 (5.0%)
Descending colon	8 (23.5%)	14 (11.7%)
Sigmoid colon	14 (41.2%)	51 (42.5%)
Rectum	22 (64.7%)	61 (50.8%)
Single/multiple			<.001
Single	17 (50.0%)	101 (84.9%)
Multiple	17 (50.0%)	18 (15.1%)

EMR, endoscopic mucosal resection.

Perioperative characteristics

Operation time and intraoperative bleeding were similar between the two groups (both P > .05). Hospital stay was longer with EMR than with conventional electrocoagulation [median, 5 (3–12) versus 4 (2–14) days, P = .02] (Table 2).

Table 2.

Perioperative Data

	EMR (N = 34)	Electrocoagulation (N = 120)	P value
Operation time (min)	24.7 ± 7.0	25.8 ± 6.5	.493
Intraoperative bleeding	6 (17.7%)	15 (12.5%)	.495
Hospital stay (days)	5 (3–12)	4 (2–14)	.022

EMR, endoscopic mucosal resection.

Adverse events

There was no intestinal perforation. Postoperative bleeding was similar between the two groups (5.9% versus 1.7%, P = .73).

Chromoendoscopy

Chromoendoscopy data were missing for some patients (n = 4 in the EMR group and n = 75 in the electrocoagulation group). In the EMR group, 19 patients were operated using chromoendoscopy, whereas only 2 patients in the electrocoagulation group were operated (Table 3). Among patients who received EMR, operation time was a little longer for those who received chromoendoscopy (27 versus 20 minutes, P = .021). There was no difference for the other variables and for the electrocoagulation group (all P > .05).

Table 3.

Subgroup Analysis

	EMR			Electrocoagulation
	Chromo (N = 19)	No chromo (N = 11)	P value	Chromo (N = 2)	No chromo (N = 43)	P value
Operation time (min)	27 (15–40)	20 (15–30)	.021	35 (30–40)	26 (15–40)	.085
Hospital stay (days)	5 (3–12)	5 (4–8)	1.000	3.5 (2–5)	4 (2–13)	.607
Intraoperative blood loss (mL)	0 (0–2)	0 (0–1.5)	.866	0 (0–0)	0 (0–15)	.618
Postoperative blood loss	0	0	1.000	0	2 (1.7%)	.933

Chromoendoscopy data were missing for some patients (n = 4 in the EMR group and n = 75 in the electrocoagulation group).

Chromo, chromoendoscopy; EMR, endoscopic mucosal resection.

Discussion

This study aimed to analyze a series of children treated with EMR or HFEC and assess the value of chromoendoscopy. Operation time and intraoperative bleeding were similar between the HFEC and EMR groups. Hospital stay was longer with EMR than with HFEC. There was no intestinal perforation in either group. Postoperative bleeding was similar between the two groups. In the EMR group, 19 patients were operated using chromoendoscopy, whereas only 2 patients were operated in the HFEC group. Chromoendoscopy led to a longer operation in the EMR group. The results suggest that EMR could be appropriate for the treatment of intestinal polyps in children.

Only very few studies reported treating colonic polyps in children with colonoscopic minimally invasive methods, and it is generally considered that the same principles apply from adults to children. With the wider application of colonoscopy in children, increasing number of flat small polyps are discovered. In addition, some large polyps require piecemeal resection under colonoscopy. We conducted all three types of EMR in children with colorectal polyps and observed no severe adverse events (such as perforation). EMR in children is specifically suitable for sessile, early, tiny, or wide-base polyps, as well as polyps at special sites that need transparent cap assistance or huge polyps that need fractional resection. Such polyps are difficult to be snared, or it is easy to snare too much intestinal tissues. As malignant change or submucosal infiltration are very rare in polyps in children, and submucosal injection easily result in a saline cushion, the percentage of the children suitable for EMR is, theoretically, higher than adults. For some short-pedicle polyps, normal saline could also be injected to form a saline cushion to increase the thickness of the intestinal wall, and thus increase the safety of EMR.

We summarize our experience of EMR in children as follows. First, appropriate bowel preparation should be performed and equipment should be readily available (titanium clip and transparent cap, if possible). To prevent intraoperative bleeding and perforation, titanium clip should be used routinely. If the site and size of the lesion are not suitable for conventional snaring, cap-assisted EMR should be considered. Second, submucosal injection during the operation is the key to prevent perforation. The site of submucosal injection should uplift the lesion but not cover the visual field. The volume of normal saline injected should be enough, and repeated multipoint injection could be performed if necessary to separate the mucosal layer from the muscular layer, and form the saline cushion. This procedure could facilitate snaring the lesion. The separation effect of the saline cushion prevents perforation. The experience from adults suggests that if the time of EMR is too long, repeated injection may be needed due to the saline absorption and loss.^9–11 Third, when the assistant is conducting the submucosal injection, we should ask him/her to inject slowly and evenly to prevent submucosal hematoma caused by too high pressure and too fast injection. If the wound is too large after the removal of the polyps, a titanium clip could be used to close the wound. Fourth, during snaring, the tissues that are not uplifted should not be snared. After the lesion is snared, the snare is fully lifted and quickly shaken, whereas the assistant opens and closes the snare several times, after which the coagulation could be conducted. The aim of this procedure is to prevent the snaring of the deep muscular layer and injuries to deep tissues. Fifth, EPMR is safer for sessile polyps >4 cm, as the snare and resection in one time for relative huge lesion are easy to snare deep tissues, and long coagulation could result in too high local temperature and lead to perforation. Sixth, we recommend using titanium clip to close the wound after EMR, especially for patients treated in the out-patient department. The patients should rest for 1 week after the operation, with the diet well controlled and bowels kept open.

Nevertheless, EMR is not suitable for all lesions in children. Indications for EMR in children with colonic polyps could be (1) Yamada type I or II sessile polyps <1 cm; (2) for wide-base polyps with base width <2 cm or some LST, EPMR could be conducted; (3) polyps at special sites and <2 cm are hard to be snared, and EMRC could be conducted; and (4) for short-pedicle polyps <2 cm, using EMR could increase the safety of electrocoagulation.

In this series, chromoendoscopy only led to a longer operation in the EMR group, which was to be expected because of the extra procedure. Chromoendoscopy had no impact on hospital stay, intraoperative blood loss, and postoperative blood loss. Of course, the sample size is probably too small to reach any firm conclusion on the matter. Nevertheless, these results suggest, for now, no added value of chromoendoscopy in these patients. These results are supported by Ravelli et al.,¹⁷ who showed that chromoendoscopy did not add any diagnostic value in children with celiac disease. Additional studies are necessary to examine this issue.

This study is not without limitations. The sample size was small and from a single center. The retrospective nature of the study prevented from analyzing data that were not recorded in the charts. In China, pediatric patients are discharged only when the patient is completely stable and there is a certainty that no adverse event will occur. This could limit the generalizability of our results to Western patients. Finally, bleeding was only qualitatively or semiquantitatively evaluated. Additional studies are necessary to confirm the benefits and safety of EMR in children.

In conclusion, EMR is a minimally invasive colonoscopic treatment method that could be used to remove effectively and completely the special types of polyps in the lower gastrointestinal tract of children.

Footnotes

Acknowledgment

This work was supported by Science and Technology of Guizhou Province [Qiankehe LH Foundation (#[2014] 7299)].

Disclosure Statement

No competing financial interests exist.

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