Introduction
The advancement in endoscopic instruments has allowed endoscopic treatment to become
the primary choice for treatment of various colorectal lesions such as polyps, laterally
spreading tumors (LSTs), and submucosal lesions (SMLs) [1]. Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) have
become the most commonly used methods for these colorectal lesions [2]
[3]
[4]. However, for lesions involving the appendiceal orifice, especially for lesions
that invade deeply into the appendiceal lumen, complete resection with EMR or ESD
is technically challenging because the distal margin cannot be fully visualized [2]
[3]
[4]. These types of lesions often require surgical interventions [5].
In recent years, endoscopic full-thickness resection (EFTR) using a specially designed
EFTR device (FTRD; Ovesco Endoscopy, Tübingen, Germany) has been introduced to dissect
lesions involving the appendiceal orifice [6]
[7]
[8]. Although it is a single-step and non-exposure procedure, the EFTR still cannot
ensure complete resection of lesions with deep invasion into the appendiceal lumen,
and may lead to a higher incidence of postoperative appendicitis [6]
[7]
[8]. Surgery may be needed for some of these patients owing to postoperative perforation
or intrabdominal abscess [6]
[7]
[8]. In 2018, Liu et al. reported the first description of full-thickness resection
of lesions involving the appendiceal orifice and simultaneous dissection of the appendix
[9], known as the endoscopic transcecal appendectomy (ETA) technique. The ETA technique
allows the appendiceal lesion to be completely resected regardless of its extension
into the appendiceal orifice, and prevents the possibility for development of postoperative
appendicitis. To date, the ETA technique has been applied to various appendiceal orifice
lesions including colonic sessile serrated lesions, appendiceal retention cysts, appendiceal
polyps, and chronic appendicitis [9]
[10]
[11]
[12]. However, previous studies on ETA have been generally small (four cases at most)
[9]
[10]
[11]
[12].
The present retrospective case series study was designed to evaluate the feasibility,
safety, and effectiveness of ETA in the management of lesions at the appendiceal orifice,
including polypoid lesions, LSTs, and SMLs.
Methods
Study design
This retrospective case series study was conducted in a tertiary hospital (West China
Hospital, Sichuan University, Chengdu, China). The study protocol was reviewed and
approved by the Biomedical Research Ethics Committee of West China Hospital, Sichuan
University.
Patients
Consecutive patients with appendiceal orifice lesions who underwent ETA in our hospital
between December 2018 and March 2021 were retrospectively reviewed from our database
of prospectively collected data. Patients with advanced carcinoma or with previous
appendectomy were excluded. All patients received a preoperative consultation with
detailed explanation of the pros and cons of different approaches including surgery,
ESD, EFTR, and the novel ETA procedure. Informed consent to undergo the ETA procedure
was obtained from all included patients.
Procedures
All ETA procedures were performed by an advanced endoscopist (B.H.), who had performed ≥ 400
colorectal ESD procedures prior to the current study. All patients underwent strict
bowel preparation to reduce intestinal contents and were treated under general anesthesia
with intubation. Before the procedures, the enteric cavities were cleaned using sterilized
water. All ETA procedures were performed using Olympus endoscopes (PCF-Q260JL/I; Olympus,
Tokyo, Japan) and routine ESD instruments: insulated-tip knife (IT knife), dual knife,
hook knife, a straight 4-mm clear cap, metal clips, and endoloop. A 20-mL syringe
with 18-G needle was also available for abdominal decompression when the endoscope
was introduced into the abdomen.
The ETA procedure involved the following steps ([Fig.1], [Fig. 2], [Video 1]): 1) circumferential marking of the lesion border using a dual knife with soft coagulation
ERBE setting; 2) near-circumferential full-thickness resection around the lesion using
dual knife and IT knife with Endocut setting; 3) introduction of the endoscope into
the peritoneal cavity through the incision in order to dissect and cut off the mesoappendix
and appendicular artery using the IT knife or hook knife; 4) snare-assisted traction
of the partially dissected appendix for continuous dissection; 5) closure of the defect
using double endoscopic suture technique after repeated cleansing of the resected
area. A nasogastric tube was inserted into the rectum for anal decompression and removed
after 2–3 days. After the procedure, patients remained fasted for at least 3 days
and received intravenous antibiotics during this period.
Fig. 1 Illustration of endoscopic transcecal appendectomy. a Near-circumferential full-thickness resection around the lesion after marking. b Introduction of the endoscope into the peritoneal cavity through the incision in
order to dissect and cut off the mesoappendix and appendicular artery. c, d Snare-assisted traction of the partially dissected appendix for adequate exposure
of the cutting line; a second endoscope was inserted for continuous dissection. e Closure of the defect using double endoscopic suture technique. Source: Eyeseemedical
Co.,Ltd, Chengdu, China.
Fig. 2 Endoscopic images of endoscopic transcecal appendectomy. a Near-circumferential full-thickness resection around the appendiceal lesion after
marking. b Dissection of the mesoappendix and appendicular artery. c Snare-assisted traction of the partially dissected appendix for adequate exposure
of the cutting line. d A second endoscope was inserted for continuous dissection. e The resected lesion and appendix. f Initial closure of the defect using purse-string suture technique. g Secondary closure of the defect using endoclips. h The healing of the defect after 1 month, with residual endoloop and endoclips.
Video 1 The endoscopic transcecal appendectomy procedure.
Outcomes and definitions
The primary outcome of the study was technical success of ETA. Secondary outcomes
included postoperative adverse events, postoperative hospital stay, and recurrence.
Technical success was defined as successful en bloc resection and R0 resection of
neoplastic lesions, and successful en bloc resection of non-neoplastic lesions. En
bloc resection was defined as resection of the lesion and the appendix. R0 resection
was defined as complete resection with negative margins. Postoperative adverse events
included postoperative bleeding, perforation, and intra-abdominal abscess (IAA). Postoperative
bleeding was defined as hemorrhage with clinical symptoms and confirmed by emergency
endoscopy from the time of procedure completion to postoperative day 28 [13]. Postoperative perforation was defined as perforation of the cecum. IAA was defined
as abscess collection inside the abdominal cavity confirmed by abdominal ultrasound
or computed tomography scan. Recurrence was defined as neoplastic lesions recurring
in the same location [14]. All cases were followed until April 2021.
Statistical analysis
Statistical analyses were conducted using SPSS version 25.0 (IBM Corp., Armonk, New
York, USA). Continuous variables were expressed as median and range. Categorical variables
were expressed as counts and percentages.
Results
A total of 13 patients with lesions at the appendiceal orifice underwent ETA during
the study period. The characteristics of patients, lesions, and outcomes are shown
in [Table 1]. There were six male and seven female patients. Ages ranged from 33 to 87 years,
with a median age of 64 years. Six patients had comorbidities and three patients had
previous history of abdominal surgery. Under colonoscopy, five lesions manifested
as polypoid lesions, four lesions were LSTs, and four lesions were SMLs (see Fig. 1 s in the online-only Supplementary material). The median lesion size was 20 mm (range
8–50). Histopathological analysis showed four adenomas, two serrated lesions, two
high grade intraepithelial neoplasias, one low grade intraepithelial neoplasia, one
low grade appendiceal mucinous neoplasm, and three cases of appendicitis.
Table 1
Characteristics of the patients, lesions, and outcomes (n = 13).
|
Age, median (range), years
|
64 (33–87)
|
|
Sex, n (%)
|
|
|
6 (46)
|
|
|
7 (54)
|
|
Comorbidity, n (%)[1]
|
6 (46)
|
|
Previous abdominal surgery, n (%)[2]
|
3 (23)
|
|
Lesion type, n (%)
|
|
|
5 (38)
|
|
|
4 (31)
|
|
|
4 (31)
|
|
Lesion size, median (range), mm
|
20 (8–50)
|
|
Histology, n (%)
|
|
|
4 (31)
|
|
|
2 (15)
|
|
|
2 (15)
|
|
|
1 (8)
|
|
|
1 (8)
|
|
|
3 (23)
|
|
Technical success, n (%)
|
13 (100)
|
|
Postoperative adverse events, n (%)
|
0 (0)
|
|
Procedure time, median (range), minutes
|
167 (90–220)
|
|
Fasting time, median (range), days
|
4 (3–13)
|
|
Postoperative hospital stays, median (range), days
|
8 (6–18)
|
|
Medical cost, median (range), yuan
|
37 219 (31 206–53 450)
|
|
Follow-up, median (range), months
|
17 (1–28)
|
|
Recurrence, n (%)
|
0 (0)
|
1 Comorbidity including hypertension, coronary heart disease, asthma, hypothyroidism,
and diabetes.
2 Previous surgery including surgery for rectal cancer and sigmoid colon cancer.
Technical success was achieved in all 13 patients. The median procedure time was 167
minutes (range 90–220). The median fasting time and postoperative hospital stay were
4 days (range 3–13) and 8 days (range 6–18), respectively. There were no cases of
postoperative bleeding, perforation, or IAA. The median medical cost during the whole
hospitalization was 37 219 yuan (range 31 206–53 450). During a median follow-up of
17 months (range 1–28), no recurrence was detected.
Discussion
This retrospective case series study showed that all 13 appendiceal orifice lesions
were successfully resected using the ETA technique, without postoperative bleeding,
perforation, or IAA, demonstrating that ETA is a feasible, safe, and effective technique
for the treatment of appendiceal orifice lesions.
With increased colon cancer screening, appendiceal and/or cecal lesions involving
the appendiceal orifice are becoming more frequently encountered [15]. Surgery, including right hemicolectomy and partial cecectomy, has often been used
as the standard therapy for these lesions. However, right hemicolectomy is associated
with relatively high postoperative complications and may be considered excessive for
relatively benign lesions such as adenomas, serrated lesions, and low grade appendiceal
mucinous neoplasms [5]
[16]. Partial cecectomy can be less invasive than hemicolectomy, but it is difficult
for the surgeon to visualize the lesion margins, thus extended resection or even right
hemicolectomy may be performed in certain cases to ensure negative margins are obtained
[5]. In addition, conversion from laparoscopic to open surgery may be needed in some
cases, which further increases medical costs and surgical trauma [17]. Compared with surgery, ETA has several potential advantages. First, endoscopists
can directly visualize the extent of the appendiceal orifice lesion, which could allow
maximum preservation of the ileocecal valve and intestine. Second, endoscopists have
more direct access to the appendiceal orifice lesion and the appendix, which could
facilitate the identification of the appendix and reduce potential injuries to surrounding
tissues, especially in patients with previous abdominal surgery. Third, the ETA technique
leaves no scar on the abdomen and has no complications associated with surgical incision,
such as incisional hernia and wound infection [18].
Endoscopic procedures such as EMR, ESD, and EFTR are also alternative treatments for
appendiceal orifice lesions [2]
[3]
[4]
[6]
[7]
[8]. However, it is not appropriate to perform EMR if the lesion margin inside the appendiceal
orifice cannot be visualized or if more than 50 % of the circumference of the appendiceal
orifice is involved [2]. R0 resection is often not achievable using the conventional ESD technique if the
lesion extends deeply into the appendiceal orifice or if the lesion involves more
than 75 % of the appendiceal orifice circumference [3]
[4]. Traction-assisted ESD can achieve higher R0 resection rates (more than 80 %) for
lesions extending into the appendiceal orifice, with short procedure times and length
of stay, but additional surgery is required in some of these patients, especially
for patients with deep invasion without previous appendectomy (27.3 %, 3/11) [19]. Recently reported single-step, non-exposure EFTR allows only partial resection
of the appendix [6]
[7]
[8], and thus residual lesion tissue may remain. Reported rates of R0 resection using
EFTR ranged from 64 % to 93 % [6]
[7]
[8]. In addition, postoperative appendicitis may develop when using ESD or ETFR for
appendiceal orifice lesions [3]
[6]
[7]
[8]. In contrast, ETA can achieve complete resection of the lesion and the appendix
simultaneously, avoiding residual lesion tissue and postoperative appendicitis. In
the present study, complete resection was achieved in all cases without postoperative
adverse events, providing direct evidence of the feasibility, safety, and effectiveness
of the ETA technique for appendiceal orifice lesions.
There are several points to note when performing the ETA procedure. First, prudent
management of the appendiceal artery helps to prevent intraprocedural bleeding. The
location of the appendiceal artery in the mesoappendix is variable. Precise mesoappendix
resection is important for prevention of accidental injury to the appendiceal artery,
especially when the mesoappendix is relatively thick. Sufficient exposure of the appendiceal
artery before coagulation is recommended in order to achieve desirable hemostasis.
Second, it is difficult to resect fat tissue in the mesoappendix, which may be due
to higher electrical resistance in fat [20]. Third, endoscopic intervention can be intrinsically challenging in this location
as any distal looping hinders endoscope maneuverability.
It is worth noting that tumor seeding may develop during ETA. The neoplasm should
be kept intact during the whole procedure. Near-circumferential full-thickness resection
around the lesion may help to reduce the risk of tumor seeding. Application of the
snare to pull the lesion into the gut may further help to minimize the possibility
of tumor seeding. For now, we recommend that the ETA technique be performed with great
caution in patients with precancerous lesions or low grade malignant neoplasms that
involve the appendiceal orifice, and it should not be performed for appendiceal orifice
lesions with deep infiltration. Therefore, detailed preoperative evaluations such
as endoscopy, endoscopic ultrasound, and computed tomography are needed to exclude
lesions with high malignancy. In addition to preoperative assessment, detailed evaluation
of the resected lesion and appendix should be performed to guide postoperative management
for these patients undergoing ETA. Close follow-up should also be performed to assess
the long-term outcomes of the ETA technique. In this study, there was no tumor recurrence
during a median follow-up of 17 months, providing preliminary evidence of the oncological
safety of ETA for appendiceal orifice lesions; however, long-term follow-up results
are needed to further confirm our findings.
There are several limitations to the study. First, the study was a retrospective case
series study. Although we consecutively collected all cases undergoing ETA in our
hospital, and the cases comprised patients with different demographic features, and
lesion morphology and pathological types, the risk of selective bias could not be
totally ruled out. Second, the sample size was relatively small for full evaluation
of this novel endoscopic approach. Further prospective studies with larger sample
sizes are needed to further assess the safety and effectiveness of the ETA procedure
for appendiceal orifice lesions. Third, we did not present intraprocedural bleeding
findings. This is mainly because intraprocedural bleeding occurred in all ETA procedures;
however, intraprocedural bleeding was less than 20 mL in all cases and was easily
controlled by endoscopic coagulation. Finally, all ETA procedures were performed by
a single advanced endoscopist, and the findings cannot therefore be generalized to
other or less experienced endoscopists.
In conclusion, ETA was shown to be feasible, safe, and effective in the management
of appendiceal orifice lesions. Large, multicenter, prospective studies are needed
to further assess this technique.
