Introduction
Superficial colorectal neoplasms are treated by endoscopic mucosal resection (EMR),
which is an internationally accepted method because of its safety and success. Nevertheless,
there are several technical limitations when treating large lesions, lesions that
span a haustral fold in the colon, or lesions that exhibit a non-lifting sign, since
this technique employs snare. [1]
[2]
[3] Instead, endoscopic piecemeal mucosal resection (EPMR) has been used for the treatment
of larger lesions; however, EPMR is associated with a residual or local recurrence
rate of approximately 6 – 27 %. [4]
[5]
[6] These residual or local recurrent tumors are treated by repeated EMR; [4]
[5]
[6]
[7] however, curative resection by repeated EMR is made difficult by the formation of
submucosal fibrosis. [6] Such lesions often require repeated therapy, with some cases requiring surgical
resection. While transanal endoscopic microsurgery (TEM) was introduced as a treatment
for large rectal adenomas and early cancers, [8] some studies have reported a recurrence rate of 3 – 19 % for patients treated with
TEM. [9]
[10]
Endoscopic submucosal dissection (ESD) is widely performed for treatment of superficial
gastric neoplasms. ESD improves a clinician’s ability to resect tissue, regardless
of lesion size or presence of peptic ulcer scar tissue. [11]
[12] In recent years, this novel technique has been used to treat colorectal cancer,
for which it has been reported to be safe and effective. [13]
[14]
[15] Moreover, en bloc resection by colorectal ESD offers an advantage over conventional
treatment due to its precise histological evaluation and the low rate of recurrence
after ESD, which is reported to be 0 – 2 %. [6]
[15]
[16] However, clinicians believe that it is more difficult to perform colorectal ESD
than gastric ESD because of the thin walls of the colon and rectum, which easily results
in perforation [17] and increases the risk of peritonitis. [18]
Some reports on gastric ESD for peptic ulcer scars have suggested the possibility
of residual or local recurrent lesions. [11]
[19]
[20] Performing colorectal ESD for residual or local recurrent tumors remains controversial
because of the technical difficulty in dissecting submucosal severe fibrosis. Some
studies have reported that severe fibrosis is the most significant risk factor for
adverse events and can interfere with en bloc resections. [21]
[22] However, if ESD is performed successfully, it can reduce the need for future surgery
and frequent follow-up examinations. Therefore, we assessed whether colorectal ESD
can be used successfully to treat residual or local recurrent tumors after previous
treatment methods, such as EMR and TEM, have been attempted.
In the current study, we sought to assess clinical outcomes with colorectal ESD for
residual or local recurrent tumors localized in therapeutic scar tissue using endoscopic
treatment (EMR, ESD, TEM) or surgery. The secondary objective was to analyze the risk
of ESD and its feasibility for use in treating residual or local recurrent colorectal
lesions.
Patients and methods
Enrolled patients
From April 2008 to September 2015, 532 consecutive superficial colorectal neoplasms
in 498 patients were treated with ESD at the Yokohama City University Medical Center.
We excluded neuroendocrine tumor (NET) cases (n = 31), cases in which ESD was interrupted
due to signs of muscle retraction [23] caused by tumor submucosal or deep invasion (n = 9), and cases of ulcerative colitis
(n = 7) or condyloma acuminatum (n = 1). As a result, we retrospectively analyzed
484 consecutive lesions from 452 cases (395 early colorectal carcinomas, 74 adenomas,
and 15 serrated lesions). There were 25 residual or local recurrent tumors localized
in therapeutic scars, of which 18 were treated by EMR, 5 were treated by TEM, 1 was
treated by ESD, and 1 was treated surgically. Patients were divided into either a
“scar group” or a “non-scar group,” and treatment outcomes and adverse events were
evaluated between the two groups. All patients provided written informed consent before
enrolling and this study was approved by the Institutional Review Board.
Indications for ESD in colorectal tumors
ESD for colorectal lesions was performed in accordance with Japan Gastroenterological
Endoscopy Society (JGES) guidelines for colorectal endoscopic submucosal dissection/endoscopic
mucosal resection. [24] Briefly, we treated lesions that were difficult to treat using endoscopic en bloc
resection with snare EMR, such as non-granular lateral spreading tumor (LST-NG); lesions
showing a Vi-type pit pattern; large, depressed-type tumors; and large protruded-type
lesions suspected to be carcinoma.
ESD procedure and technique
Colorectal ESD was performed by 5 experienced gastrointestinal endoscopists who have
performed more than 100 gastric ESDs, 30 esophageal ESDs, and 2000 colonoscopies.
We mainly used a water-jet system-furnished colonic endoscope (PCF-Q260AZI; Olympus,
Tokyo, Japan) for all lesions other than rectal lesions, which were treated using
an upper gastrointestinal endoscope with a water-jet system (GIF-Q260J; Olympus).
We introduced a carbon dioxide insufflation system in March 2008 to relieve abdominal
discomfort of patients and to avoid abdominal compartment syndrome in the event of
perforation. [25] In all procedures, a 1.5-mm Dual knife (KD650Q; Olympus) was used. A Hook knife
(KD-260R; Olympus) was also used in the scar group. The electrosurgical unit ICC200
(ERBE, Tübingen, Germany) was used in two modes: ‘endocut’ mode (60 W, effect 3) and
‘forced coagulation’ mode (40 W). We used a 0.4 % sodium hyaluronate solution [26] for submucosal injections in all cases. During the procedure, a 4-mm-long transparent
hood was systematically attached to the tip of the endoscope (D-201 – 11804; Olympus)
to facilitate optimal field visualization and stable dissection. A small caliber-tip
transparent hood (ST hood short type) (DH-29CR; Fujifilm, Tokyo, Japan) was used for
all participants in the scar group to facilitate the entry of endoscopic devices into
the submucosal layer. Colorectal tumors were usually not marked since the border between
the lesion and normal mucosa was clear upon visualization with indigo carmine or narrow
band imaging (NBI). However, all tumors in the scar group were marked so as to initiate
dissection in tissue without scar-induced submucosal fibrosis. Therefore, in the scar
group, markings were often made less than 10 mm away from the tumor margin. During
the submucosal dissection, we carefully dissected the fibrotic part. We used the Hook
knife to prevent perforation in cases in which fibrosis was prevalent ([Fig. 1]). Meticulous hemostasis was performed when intraoperative bleeding occurred. Endoscopic
clipping was used to treat intraoperative perforations.
Fig. 1 The images are of a patient who received a rectal EPMR 5 years ago. a, b Conventional imaging of the recurrent tumor in Rb revealed a flat, elevated lesion
with scar tissue. c During ESD, severe fibrosis was observed in the submucosa at the site of the scar
that formed following the previous EPMR. d, e ESD was achieved by en bloc resection without perforation. The procedure time was
155 minutes. f Histological findings showed well-differentiated adenocarcinoma tissue confined within
the mucosa and measuring 48 mm in diameter, with severe fibrosis beneath the tumor.
Terminology and definition related to treatment
En bloc resection indicates tumor resection in 1 piece. R0 resection indicates en
bloc resection wherein the lateral and vertical margins of the specimens are free
of tumor cells. Curative resection indicates that: (i) a R0 resection was completed;
(ii) the lesion was an adenoma, papillary adenocarcinoma, or tubular adenocarcinoma;
(iii) intramucosal colorectal neoplasm or submucosal invasion was less than 1000 μm
deep; (iv) the lymphatic or vascular systems were not involved; and (v) the budding
was grade 1 if the tumor invaded into the submucosa. [27] Perforation was indicated by extra-intestinal tissue projecting through a hole during
treatment and/or the presence of empty space upon postoperative abdominal XP or CT.
Post ESD bleeding was identified by the presence of bloody stool at any time point
after ESD and by the need for endoscopic hemostasis, regardless of the outcome of
hemostasis.
The right colon included the cecum, ascending colon, and transverse colon; the left
colon included the descending colon, sigmoid colon, and rectosigmoid colon; and the
rectum included the Ra and Rb. Tumor morphology included granular lateral spreading
tumor (LST-G) and LST-NG, as indicated by the Kudo classification, or protruding tumor
(0-Is/Ip), as indicated by the Paris classification. [28]
[29] Histology included either tubular adenoma, tubular adenocarcinoma, or serrated lesion.
The depth of the tumor was categorized as either a mucosal lesion (Tis), a submucosal
invasion lesion < 1000 µm from the muscularis mucosae (T1a), or a submucosal invasion
lesion ≥ 1000 µm from the muscularis mucosae (T1b). The non-tumor size was defined
as the maximum diameter of the non-tumor mucosa, which indicated the sum of the major
axes of the non-tumor mucosa in the sections in which the tumor was at its maximum
diameter.
Indications for using ESD to treat residual or local recurrent lesions
Residual or local recurrent lesions were defined as lesions at the same site after
previous endoscopic treatment (i. e., EMR, ESD), TEM, or surgery; previous pathological
examination indicating the presence of superficial colorectal tumor tissue, including
adenoma, intramucosal carcinoma, or carcinoma, with submucosal invasion of less than
1000 μm in depth, and without lymphvascular invasion, namely, the absence of non-curative
factors in previous pathological examinations only except lateral margin; a lesion
without invasion, as indicated by macroscopic endoscopic evaluation according to the
Paris morphological and Kudo classifications, [28]
[29] regardless of tumor morphology; a lesion that was difficult to resect using conventional
EMR in en bloc fashion; and confirmed absence of evidence of metastasis or recurrence
in a whole body CT and no increase of tumor markers, if pathological results from
previous treatments from more than five years ago could not be obtained.
Histopathological evaluation
All specimens were “pinned out” onto polystyrene receivers to facilitate subsequent
histopathological sectioning prior to immediate fixation in 10 % buffered formalin
solution and were also cut into 2-mm-wide slices the following day. The fragments
or slices were embedded in paraffin, cut into 3-μm sections, stained with hematoxylin
– eosin, and microscopically examined for histologic type.
Post ESD follow-up protocol
All resected cases were followed up with endoscopic examinations within six months
after ESD. Patients then received endoscopic examinations annually, which allowed
for the assessment of the presence of local recurrence. Recurrence was defined as
new visible tumor on a therapeutic scar more than 6 months after treatment.
Statistical analysis
Statistical analyses were performed using SPSS 22.0 (SPSS Inc., Chicago, IL, USA).
Continuous variables were expressed as the mean ± standard deviation (SD) or medians
and ranges. Categorical parameters were expressed as numbers and frequencies. The
rate of en bloc resection, the rate of R0 resection, the rate of curative resection,
the rate of perforation, the rate of post-operative bleeding, and mean treatment time,
were compared between the two groups. Categorical parameters were statistically compared
using the chi-square test and the Fisher exact test, and continuous parameters were
compared using Student’s t-test. To identify factors associated with perforation and
prolonged treatment time, clinicopathological factors were compared. Those variables
with a P value < .05 in the univariate analysis were examined in multivariate logistic regression
models. Odds ratios (ORs) and 95 % confidence intervals (CIs) were calculated using
a logistic regression analysis. P values < .05 were considered statistically significant.
Results
Clinicopathological characteristics of patients are shown in [Table 1]. We compared sex, average age, location of tumor, morphology, histology, depth of
tumor invasion, average tumor size, average specimen size, and average non-tumor size
between the scar and non-scar groups. The 2 groups did not differ by sex, age, tumor
location, tumor morphology, histology, tumor depth, and specimen size. Tumor size
was significantly larger and non-tumor size was significantly smaller in the non-scar
group. Evaluation of previous histological reports in the scar group identified eight
cases of tubular adenoma, 11 cases of tubular adenocarcinoma confined to mucosa without
lymphovascular invasion, and 6 cases of unknown histological information since previous
treatment was performed more than 5 years ago and there was no evidence of metastasis
at the time of treatment in our hospital.
Table 1
Clinicopathological characteristics of all patients (n = lesions).
|
Scar group
(n = 25)
|
Non-scar group
(n = 459)
|
P value
|
|
Sex
|
|
|
0.238
|
|
|
17
|
257
|
|
|
|
8
|
202
|
|
|
Age (average)
|
47 – 84 (72)
|
30 – 95 (69)
|
0.26
|
|
Tumor location
|
|
|
0.773
|
|
|
14
|
254
|
|
|
|
3
|
78
|
|
|
|
8
|
127
|
|
|
Tumor morphology
|
|
|
0.732
|
|
|
4
|
50
|
|
|
|
11
|
213
|
|
|
|
10
|
196
|
|
|
Histology
|
|
|
0.328
|
|
|
6
|
68
|
|
|
|
19
|
376
|
|
|
|
0
|
15
|
|
|
Tumor depth
|
|
|
0.109
|
|
|
25
|
419
|
|
|
|
0
|
40
|
|
|
Tumor size (average) mm
|
6 – 75 (24)
|
5 – 130 (33)
|
0.011
|
|
Specimen size (average) mm
|
30 – 75 (48)
|
15 – 150 (43)
|
0.101
|
|
Non-tumor size (average) mm
|
0 – 63 (24)
|
0 – 35 (9)
|
< 0.001
|
[Table 2] indicates treatment outcomes between the scar and non-scar groups. En bloc resection
rate (96 % and 99.6 %), R0 resection rate (84.0 % and 91.7 %), and curative resection
rate (84.0 % and 84.3 %) did not differ between both groups. Intraoperative perforation
rate was significantly higher in the scar group (32 % in the scar group and 4.1 %
in the non-scar group). Conversely, postoperative bleeding did not differ (0 % and
3.5 %). Moreover, treatment time in the scar group was approximately twice as long
compared to the non-scar group. All cases of intraoperative perforation were conservatively
managed after endoscopic closure using endoclips, and no cases required emergent surgery
nor were there any cases of uncontrolled intraoperative or postoperative bleeding.
There were no deaths related to ESD. The median length of hospital stay was four days
(range 4 – 8 days).
Table 2
Treatment outcomes between the scar and non-scar groups.
|
Scar group
(n = 25)
|
Non-scar group
(n = 459)
|
P value
|
|
En bloc resection, n (%)
|
24 (96.0)
|
457 (99.6)
|
0.147
|
|
R0 resection, n (%)
|
21 (84.0)
|
421 (91.7)
|
0.259
|
|
Curative resection, n (%)
|
21 (84)
|
387 (84.3)
|
1.000
|
|
Perforation, n (%)
|
8 (32)
|
19 (4.1)
|
< 0.001
|
|
Post-operative bleeding, n (%)
|
0 (0.0)
|
16 (3.5)
|
1.000
|
|
Treatment time (average) min.
|
24 – 210 (117)
|
10 – 273 (61)
|
< 0.001
|
We compared the results of previous treatments, including EMR (n = 18), TEM (n = 5),
ESD (n = 1),
and surgery (n = 1) in the scar group ([Table 3]). The average tumor size of participants in the post-TEM group was larger than that
of the post-EMR group. Therefore, treatment time was longer in the post-TEM group
compared with the post-EMR group. However, the perforation rate in the post-TEM group
was lower than in the post-EMR group. Additionally, the rate of curative and R0 resection
in the post-EMR group and post-TEM group was similar.
Table 3
Clinicopathological characteristics and treatment outcomes of previous treatments
of patients in the scar group
|
post-EMR (n = 18)
|
post-TEM (n = 5)
|
Others (n = 2)
|
|
Tumor morphology (0-IIa / 0-I)
|
16/2
|
4/1
|
2/0
|
|
Histology (adenoma/adenocarcinoma)
|
4/14
|
2/3
|
0/2
|
|
Tumor size mm
(average)
|
6 – 48
(19)
|
7 – 75
(45)
|
16 – 30
(23)
|
|
Specimen size mm
(average)
|
30 – 74
(44)
|
45 – 75
(65)
|
36 – 65
(51)
|
|
Tumor depth (Tis · T1a / T1b)
|
18/0
|
5/0
|
2/0
|
|
R0 resection, n (%)
|
16 (89)
|
4 (80)
|
1(50)
|
|
Curative resection, n (%)
|
16 (89)
|
4 (80)
|
1(50)
|
|
Perforation, n (%)
|
6 (33)
|
1 (20)
|
1 (50)
|
|
Treatment time min.
(average)
|
24 – 210
(107)
|
115 – 175
(145)
|
105 – 195
(150)
|
Factors indicating treatment difficulty
The above-described results indicate the efficacy of ESD, as indicated by the favorable
en bloc, R0, and curative resection rates, as well as the increased perforation rate
and longer treatment time compared to the scar group. Thus, we hypothesized that therapeutic
failure caused by technical difficulties could be indicated by perforation rate and
treatment time. Therefore, we evaluated factors potentially affecting perforation
and treatment time ( ≥ 90 min) and, thus, reflecting the difficulty of performing
ESD. The factors of sex, age, tumor location, tumor morphology, tumor depth, tumor
size, and scar presence following previous treatment were examined by univariate and
multivariate analysis ([Table 4] and [Table 5]). In doing so, we identified which factors predict treatment difficulty. Tumors
located in regions other than the rectum and the presence of post-therapeutic scar
tissue was an independent risk factor of perforation. The odds ratio for presence
of post-therapeutic scar tissue was elevated (18.052; 95 % CI: 5.889 – 55.341). Tumor
size and the presence of post-therapeutic scar tissue were independent risk factors
that indicate prolonged treatment time. The odds ratio for presence of post-therapeutic
scar tissue was 43.283 (95 % CI: 14.19 – 132.58).
Table 4
Comparison of clinocopathological characteristics of resections involving perforation.
|
non-perforation
|
perforation
|
Univariate
|
Multivariate
|
|
P value
|
P value
|
OR (95 % CI)
|
|
Sex
|
|
|
0.775
|
|
|
|
|
258
|
16
|
|
|
|
|
|
199
|
11
|
|
|
|
|
Age, years
|
|
|
0.969
|
|
|
|
|
303
|
18
|
|
|
|
|
|
154
|
9
|
|
|
|
|
Tumor location
|
|
|
0.041
|
0.019
|
|
|
|
258
|
18
|
|
1 (reference)
|
|
|
|
68
|
7
|
|
0.42
|
1.485 (0.569 – 3.867)
|
|
|
131
|
2
|
|
0.026
|
0.178 (0.039 – 0.812)
|
|
Tumor morphology
|
|
|
0.583
|
|
|
|
|
50
|
4
|
|
|
|
|
|
214
|
10
|
|
|
|
|
|
193
|
13
|
|
|
|
|
Tumor depth
|
|
|
0.868
|
|
|
|
|
419
|
25
|
|
|
|
|
|
38
|
2
|
|
|
|
|
Tumor size
|
|
|
0.764
|
|
|
|
|
115
|
8
|
|
|
|
|
|
236
|
12
|
|
|
|
|
|
106
|
7
|
|
|
|
|
Scar
|
|
|
< 0.001
|
|
|
|
|
440
|
19
|
|
1 (reference)
|
|
|
|
17
|
8
|
|
< 0.001
|
18.052 (5.889 – 55.341)
|
Table 5
Comparison of clinicopathological characteristics of resections with a prolonged treatment
time (≥ 90 min).
|
Time ≤ 90 min
|
Time > 90 min
|
Univariate
|
Multivariate
|
|
P value
|
P value
|
OR (95 % CI)
|
|
Sex
|
|
|
0.429
|
|
|
|
|
211
|
63
|
|
|
|
|
|
168
|
42
|
|
|
|
|
Age, years
|
|
|
0.309
|
|
|
|
|
247
|
74
|
|
|
|
|
|
132
|
31
|
|
|
|
|
Tumor location
|
|
|
0.154
|
|
|
|
|
217
|
51
|
|
|
|
|
|
64
|
17
|
|
|
|
|
|
98
|
37
|
|
|
|
|
Tumor morphology
|
|
|
0.006
|
|
|
|
|
46
|
8
|
|
1 (reference)
|
|
|
|
161
|
63
|
|
0.201
|
1.744 (0.737 – 4.274)
|
|
|
172
|
34
|
|
0.431
|
1.441 (0.581 – 3.574)
|
|
Tumor depth
|
|
|
0.596
|
|
|
|
|
349
|
95
|
|
|
|
|
|
30
|
10
|
|
|
|
|
Tumor size
|
|
|
< 0.001
|
|
|
|
|
105
|
18
|
|
1 (reference)
|
|
|
|
207
|
41
|
|
0.055
|
4.076 (0.984 – 4.378)
|
|
|
67
|
46
|
|
< 0.001
|
7.059 (3.072 – 16.225)
|
|
Scar
|
|
|
< 0.001
|
|
|
|
|
374
|
85
|
|
1 (reference)
|
|
|
|
5
|
20
|
|
< 0.001
|
43.283(14.19 – 132.58)
|
Long-term clinical result
In the non-scar group, 89 % of patients (383 /430) underwent scheduled examinations,
while the remaining patients were lost by the time of endoscopic follow up. The median
follow-up time was 20 months (range: 9 – 87 months). No patients in the scar group
were lost by the time of follow-up after ESD. The median follow-up time was 24 months
(range: 9 – 59 months). No cases of recurrent tumor formation were observed in the
non-scar group, while one case was observed in the scar group. The patient with recurrence
in the scar group was treated by performing two-piece resection after TEM.
Discussion
The first aim of the current study was to compare the scar and non-scar groups in
order to evaluate the technical feasibility, safety, and efficacy of ESD. This study
indicated that en bloc and R0 resections were successfully performed in the scar group
in comparison with the non-scar group. This result is similar to previous reports
that indicated that the R0 resection rate for residual or local recurrent tumor was
83 – 96.4 %. [30]
[31]
[32] In addition, because all the tumors in the scar group were intramucosal, the curative
resection rate was equal to the R0 resection rate, which was also increased. Because
previous histological evaluation is important for treating residual or local recurrent
lesions, we confirmed that most histopathological findings indicated intramucosal
cancer or tubular adenoma in the scar group, which accounted for our positive findings.
Despite the significantly smaller size of the tumors in participants in the scar group,
similarly sized tissue was resected in both groups, thereby indicating that the size
of non-tumor tissue was significantly larger in the scar group. This was due to our
dissection into healthy submucosal tissue that does not exhibit fibrotic tissue in
order to ensure a sufficient margin for dissecting submucosal tissue. If we were to
encounter submucosal fibrosis after performing the circumference incision, we would
have become disoriented, which can result in tumor incision directly or perforation.
This is central to the safe and effective completion of ESD with a high en bloc and
R0 resection rate in the scar group. We also use the tapered attachment hood (ST hood)
and Hook knife to perform ESD for all patients in the scar-group. This combination
allows for a reliable view and avoids perforation. However, because the field of view
becomes narrower, this equipment is usually not required in the non-scar group. Despite
the high en bloc and R0 resection rate, we could not avoid a high perforation rate
and a longer procedure time in the scar group. The high perforation rate of 32 % in
the present study was higher than previous reports. This is likely due to the small
sample size, which could have greatly affected the rate of perforation. Additionally,
the rate of 0 % reported by Hurlstone DP et al. [31] and 3.6 % by Gabriel RAHMI et al. were too low because even the perforation rate
of ordinary colorectal ESD has been reported to be approximately 5 % [13]
[14]
[15]
[17]. Due to severe fibrosis and insufficient submucosal injection, it was difficult
to visualize the laminar structure of the colorectal wall. Several breakthroughs are
needed for this procedure to be safer and more effective.
We next analyzed incidence of perforation and prolonged procedure time in all subjects
to clarify the technical difficulty of ESD for the scar group. Multivariate analysis
indicated that tumors located in the colon, but not the rectum, and those with scars
formed by previous interventions are both risk factors for perforation. Sub-analysis
indicated that perforation occurs easily in the descending colon near its junction
with the sigmoid colon (15 %, data were not shown). ESD of lesions located at the
sigmoid-descending junction is more difficult to treat than are those in other colorectal
regions due to the mobility of the endoscope. In an analysis of prolonged treatment
time, larger lesions and therapeutic scars were also found to be independent risk
factors. This suggests that ESD for large lesions requires a longer treatment time,
but is safe due to the low risk of perforation. In conclusion, because the therapeutic
scar is an independent risk factor of a prolonged procedure time and perforation,
a unique technique was required.
In comparing post-EMR groups and post-TEM groups, the perforation rate was found to
be lower in post-TEM groups despite the larger average size of resected tissue and
longer treatment time in post-TEM groups. This was often due to the rectal-located
residual or local recurrent tumors in patients in the post-TEM group, which made them
easier to treat. Moreover, the rate of curative and R0 resection in the post-EMR group
and post-TEM group was almost the same. Because previous reports of colorectal ESD
for residual or local recurrent tumors were limited to reports of ESD after EMR, [30]
[31]
[32], the current study is the first report that ESD is an effective therapy for not
only endoscopic therapy, but also for post-TEM. Furthermore, clinicians can avoid
performing a second TEM, which requires general anesthesia. However, given the small
number of patients in the post-TEM group, further investigation is necessary to evaluate
the effectiveness of ESD for post-TEM.
We next assessed long-term outcomes. In doing so, we did not observe local recurrence
confined to the R0 resected cases both in the scar and non-scar groups. However, we
observed 1 case of a local recurrent lesion, which was previously treated using ESD.
This case was initially treated in a previous hospital using TEM 19 years prior to
admission. Then a local recurrent tumor developed on the treatment scar, which appeared
as a type 0–IIa that was 65 mm diameter and was treated using ESD in our hospital.
The lesion was resected with two specimens due to severe fibrosis. The pathological
diagnosis showed tubular adenocarcinoma confined to the mucosa with unknown horizontal
margin caused by piecemeal resection. It was possible that undetected tumor cells
remained in the ulcer bed. After 1 year, the tumor re-occurred as a type 0-IIa that
was 15 mm diameter on the ESD scar and was treated using ESD. Repeated ESD was performed
for this lesion by en-bloc resection. Final pathological diagnosis showed tubular
adenocarcinoma confined to the mucosa that was negative for the horizontal margin.
Other treatments for residual or local recurrent colorectal tumors include Laparoscopic
Endoscopic Cooperative Surgery (LECS) or laparoscopic colorectal surgery (LAC). [33] The advantage of LECS is that it involves a local excision with adequate minimal
surgical margins; however, the disadvantage of LECS is that it requires general anesthesia
and the necessity of additional treatment when the tumor showed submucosal invasion.
LAC can be used for tumor and regional lymph node removal; however, it could be overly
aggressive for tumors confined to the mucosa. In both, surgical adverse events, such
as anastomotic leakage or appearance of a rectal tumor near the anus, require Miles
operation and colostomy. [34]
[35] Colorectal ESD is always performed under conscious sedation, therefore, there was
no fear of perioperative adverse events, such as pneumonia or barotrauma.
In the current study, ESD for residual or local recurrent lesions allows for en bloc,
R0 and curative resection. This result contributes the most beneficially to ESD, which
allows for pathological evaluation and is free from neoplastic cells. However, perforation
rate is significantly higher and requires a prolonged treatment time than in comparable
groups. In addition, presence of a therapeutic scar is an independent risk factor
for perforation and prolonged procedure time. Fortunately, all perforations were treated
with endoscopic closure by clipping and with prescribed antibiotics. Therefore, no
patient experiencing perforation required emergent surgery. Furthermore, the subsequent
hospitalization was less than 1 week. This indicated that ESD for residual or local
recurrent tumors may be a treatment choice that requires meticulous attention.
Limitations of the current study were as follows:
-
This was a retrospective study conducted at a single institution.
-
The sample size of the scar group was small.
-
This study investigated patients over the course of 7 years. Therefore, the endoscopist’s
skill had been improved during this period. This might affect treatment outcome.
Conclusion
In conclusion, this study suggests that colorectal ESD can be used as a treatment
choice for residual or local recurrent tumors; however, it can only be performed in
specialized hospitals. Furthermore, ESD can be performed depending upon the risk for
perforation and requires cooperation with other surgical departments when treating
colorectal residual or recurrent tumors.
