Keywords
Endoscopy Lower GI Tract - Colorectal cancer - Endoscopic resection (polypectomy,
ESD, EMRc, ...)
Introduction
Endoscopic submucosal dissection (ESD) has significantly advanced management of gastrointestinal
lesions, enabling en bloc resection regardless of lesion size [1]
[2]
[3]
[4]
[5]. This progress is supported by improvements in procedural techniques and introduction
of innovative equipment, which together have led to a decrease in the rate of intraprocedural
adverse events (AEs). Despite these advances, challenges such as post-ESD bleeding,
delayed perforation, and post-ESD coagulation syndrome (PECS) due to transmural electrocautery
burns still present risks in colon procedures, occasionally requiring emergency interventions
and extending hospital stays [6].
Prophylactic clip closure following colorectal endoscopic resection has been effectively
shown to reduce incidence of adverse AEs [7]
[8]
[9]
[10]. Innovations in endoscopic closure techniques have significantly enhanced endoscopists’
ability to manage and seal mucosal defects reliably [11]
[12]
[13]
[14]
[15]
[16]
[17]
[18]
[19]
[20]. The MANTIS Clip (Boston Scientific, Marlborough, Massachusetts, United States)
is a recently introduced, novel anchor-pronged clip distinguished by its strong tissue
grasping capability. While the effectiveness of this novel clip in sealing gastric
post-procedural defects, stent fixation in the esophagus, and closure after colorectal
ESD (C-ESD) has been documented, it remains limited to a few case reports [21]
[22]
[23]
[24]
[25].
This study aimed to evaluate the effectiveness and practicality of the MANTIS Clip
in closing mucosal defects following C-ESD, with a particular focus on assessing its
feasibility and efficacy.
Patients and methods
This retrospective, single-center study was conducted using prospectively collected
data between May 2023 and April 2024 at Showa University Koto Toyosu Hospital, a tertiary
referral center in Tokyo, Japan. All patients who underwent C-ESD with mucosal defect
closure using MANTIS Clip was included. The study complied with the Declaration of
Helsinki and received approval from the Institutional Review Board of Showa University
(approval number 2023–297-A). Written informed consent was obtained from all participants.
C-ESD procedure
We adhered to the Japan Gastroenterological Endoscopy Society (JGES) guidelines for
C-ESD indications [26]. The C-ESD procedure was conducted using a therapeutic endoscope equipped with a
waterjet function (PCF-H290TI; Olympus Medical Systems, Tokyo, Japan) under carbon
dioxide insufflation. A distal attachment was utilized, either the ST Hood Short-type
(DH-28GR; Fujifilm, Tokyo, Japan) or a disposable distal attachment (D-201–11804;
Olympus Medical Systems, Tokyo, Japan). Submucosal injection was achieved using 4%
sodium hyaluronate (MucoUp; Boston Scientific, Marlborough, Massachusetts, United
States) for the initial injection, supplemented as needed with normal saline mixed
with indigo carmine to enhance tissue contrast. The mucosal incision and submucosal
dissection were performed using a 2-mm ProKnife (Boston Scientific, Marlborough, Massachusetts,
United States). Electrocautery was provided by the VIO300D unit (Erbe Elektromedizin,
Tübingen, Germany), employing an Endo cut I (effect 2) for mucosal incisions, swift
coagulation (effect 2, 45W) for submucosal dissection, or spray coagulation (effect
2, 45W) for achieving hemostasis with the knife tip. In our C-ESD procedures, we employed
three methods based on lesion characteristics: the pocket creation method [27], bridge formation method [28], and water pressure method [29]. The choice of method, or combination of methods, was decided by the endoscopist
performing the ESD. In the event of a perforation during the procedure, any defects
in the muscularis layer were promptly closed using conventional endoclips. C-ESD were
performed by a team of endoscopists, including two experts and six trainees. Antithrombotic
therapy peri-ESD treatment was managed according to the JGES guidelines [30].
Closure method utilizing MANTIS Clip
The closure technique was implemented immediately following C-ESD, without withdrawal
and reinsertion of the colonoscope. This procedure involved aligning the center of
the mucosal defect along the longitudinal axis of the lumen using MANTIS clips ([Fig. 1]). A MANTIS Clip was applied to grasp one edge of the defect and then drawn toward
the opposite edge using endoscope manipulation. The anchor prong at the tip of the
clip prevented the pulled tissue from slipping out when the clip was reopened, allowing
it to close over the contralateral edge. After the defect edges were approximated,
additional conventional clips (SureClip, 8-mm; MicroTech, Nanjing, China) were deployed
starting from near the MANTIS Clip, gradually extending across the defect, ultimately
achieving complete closure ([Fig. 2], [Fig. 3], [Video 1]).
Fig. 1 Detailed views of the MANTIS Clip. a Image of the MANTIS Clip in the open position, with an opening width of 11 mm. b Oblique view of MANTIS Clip grasping arms. c Detailed view of the tip of the arm, highlighted in the red box in image (b), which
has an anchor prong and a MANTIS-like claw designed to enhance gripping strength.
Fig. 2 Demonstration of mucosal defect closure using the MANTIS Clip in an ex-vivo model.
a Overview of an ex-vivo setup showing a mucosal defect model, an endoscopic scope,
and the MANTIS Clip, illustrating the initial setup for defect closure. b Application of the MANTIS Clip to grasp one side of the mucosal defect securely.
c The endoscope is carefully dragged to the opposite side while maintaining a firm
grasp on the mucosa with the clip. d Reopening of the MANTIS Clip; the mucosa remains securely held by the hook of the
clip’s arm. e Closure of the clip, capturing the mucosa from the opposite side to ensure comprehensive
closure of the defect. f Effective approximation of the defect's center by the MANTIS Clip, demonstrating
the clip’s capability in facilitating mucosal defect closure.
Fig. 3 Closure of a colonic mucosal defect after ESD. a A 30-mm post-ESD defect in the ascending colon. b The mucosal edge on the anal side of the defect is grasped with the MANTIS Clip.
c The lumen is suctioned and the mucosa on the anal side is dragged toward the opposite
side while holding it with the MANTIS Clip. d Upon opening the MANTIS Clip, the mucosa on the anal side is securely hooked onto
the MANTIS Clip. e After suturing, the wound is tightly closed in the center of the defect. f Conventional
clips were added to achieve complete closure.
Closure of 40-mm post-ESD mucosal defects in the ascending and transverse colon. This
video presents the closure techniques for two 40-mm mucosal defects following ESD,
one in the ascending colon and the other in the transverse colon. It illustrates step-by-step
procedural strategies, deployment of the closure device, and final outcomes for each
case. The video highlights the adaptability and effectiveness of the closure method
across different anatomical locations within the colon.Video 1
Outcome measures and definitions
The primary outcome measured was the success rate for complete closure, with secondary
outcomes including the size of the closed defect, sustained closure rate, time taken
for complete closure, number of clips used, incidence of AEs, C-reactive protein levels
on the first day post-ESD, and duration of hospital stays post-ESD.
In this study, complete closure rate was defined as complete coverage of the defect
ulcer base by mucosa using the MANTIS Clip alongside additional conventional clips.
The sustained closure rate was assessed by absence of a visible ulcer base during
follow-up colonoscopy 4 to 5 days after C-ESD. Closure time was measured from insertion
of the first MANTIS Clip until full closure of the defect was achieved. Delayed bleeding
was identified as hematochezia that necessitated endoscopic hemostasis post-ESD. Delayed
perforation was characterized by sudden onset of severe abdominal pain accompanied
by peritoneal or retroperitoneal free air on a computed tomography scan post-C-ESD,
without evidence of perforation during the procedure. PECS was defined as localized
abdominal pain and fever (> 37.6°C, leukocytosis (> 10,000/μL), or elevated CRP levels
(> 0.5 mg/dL) occurring post-procedure without clear evidence of perforation [31].
Statistical analysis
Statistical analyses were performed using JMP Pro 16 (SAS Institute Inc., Cary, North
Carolina, United States). Categorical data were represented as frequencies and percentages,
while continuous and nonparametric variables were presented as medians with interquartile
ranges or overall ranges.
Results
Patient and lesion characteristics
The MANTIS Clip was utilized in 52 cases for the closure of mucosal defects after
C-ESD during this study period. [Table 1] provides detailed patient demographics and lesion characteristics. The median age
of the patients was 68 years (IQR 57.75–75; range 28–88 years), consisting of 27 males
(51.9%) and 25 females (48.1%). Regarding antithrombotic therapy, five patients (9.6%)
were receiving treatment: two patients (3.8%) were on Aspirin, one patient (1.9%)
on other antiplatelet drugs, one patient (1.9%) on warfarin, and two patients (3.8%)
on direct oral anticoagulants. Lesion locations included the cecum (4; 7.7%), ascending
colon (20; 38.5%), transverse colon (13; 25.0%), descending colon (2; 3.8%), sigmoid
colon (10; 19.2%), and rectum (3; 5.8%). The median lesion size was 24 mm (IQR 17.75–29.25;
range 13–53 mm). Histological classifications were serrated lesions (9; 17.3%), low-grade
tubular adenoma (8; 15.4%), high-grade tubular adenoma to intramucosal cancer (31;
59.6%), and submucosal cancer (4; 7.7%). Complications during ESD, such as injury
to the muscle layer, occurred in five cases (9.6%).
Table 1 Patient and lesion characteristics. (N = 52)
Characteristics
|
Values
|
IQR, interquartile range; DOAC, direct oral anticoagulant; Ra, rectum above the peritoneal
reflection; Rb, rectum below the peritoneal reflection; ESD, endoscopic submucosal
dissection.
|
Age, median (IQR, range), years
|
68 (57.75–75, 28–88)
|
Gender, male/female
|
27 / 25
|
Use of oral antithrombotic agent, n (%)
|
5 (9.6%)
|
|
2 (3.8%)
|
|
0 (0%)
|
|
1 (1.9%)
|
|
1 (1.9%)
|
|
2 (3.8%)
|
Location, n (%)
|
|
|
4 (7.7%)
|
|
20 (38.5%)
|
|
13 (25.0%)
|
|
2 (3.8%)
|
|
10 (19.2%)
|
|
3 (5.8%)
|
|
1 (1.9%)
|
|
0 (0%)
|
|
2 (3.8%)
|
Size of the lesion, median (IQR, range), mm
|
24 (17.75–29.25, 13–53)
|
Histology, n (%)
|
|
|
9 (17.3%)
|
|
8 (15.4%)
|
|
31 (59.6%)
|
|
4 (7.7%)
|
Complication during ESD (injury to the muscle layer)
|
5 (9.6%)
|
Closure technique results
The results of the closure techniques are summarized in [Table 2]. The complete closure rate was 98.1% (51/52), and the sustained closure rate was
96.1% (49/51). The median size of the closed defect was 32 mm (IQR 27.75–39.25 mm;
range 16–62 mm), and the median time for complete closure was 8 minutes (IQR 6–10.25
minutes). The median number of MANTIS clips used per defect was 1 (range 1–2). Only
one lesion, a 40-mm defect in the transverse colon, required the use of 2 MANTIS clips
([Video 1]). Notably, a dead space formed under the mucosa in one case (1.9%), necessitating
the removal of the MANTIS Clip and subsequent closure with conventional clips. In
a separate instance involving the sigmoid colon, the arm of the MANTIS Clip broke
during the procedure; however, successful defect closure was achieved using a second
MANTIS Clip. The median number of additional clips used was seven (IQR 5–8.25). Post-procedural
AEs included one case of bleeding (1.9%) in a patient on dual anticoagulation therapy
(edoxaban and prasugrel), which was successfully managed with endoscopic clipping.
There was also one case of PECS (1.9%) in the cecum, which resolved with antibiotics
by the third postoperative day without extending the hospital stay. Both patients
recovered without further complications. The median C-reactive protein (CRP) level
on the first day post-ESD was 0.35 mg/dL (IQR 0.1–1.51 mg/dL), and the median duration
of hospital stay post-ESD was 5 days (IQR 4–5 days).
Table 2 Patient and lesion characteristics. (N = 52)
Closure technique results
|
Values
|
IQR, interquartile range; ESD, endoscopic submucosal dissection; CRP, C-reactive protein.
|
Size of the closed defect, median (IQR, range), mm
|
32 (27.75–39.25, 16–62)
|
Complete closure success rate, n (%)
|
51/52 (98.1%)
|
Sustained closure rate, n (%)
|
49/51 (96.1%)
|
Time for complete closure, median (IQR), min
|
8 (6–10.25)
|
Number of MANTIS clips used, median (IQR, range)
|
1 (1–1, 1–2)
|
Number of additional clips used, median (IQR)
|
7 (5–8.25)
|
Post-procedural adverse events
|
|
|
0 (0%)
|
|
1 (1.9%)
|
|
1 (1.9%)
|
|
0 (0%)
|
CRP level (mg/dL) on the first day post-ESD, median (IQR)
|
0.35 (0.1–1.51)
|
Duration of hospital stays after ESD, days, median (IQR)
|
5 (4–5)
|
Discussion
This study demonstrated that the MANTIS Clip achieves a high success rate of complete
closure and a sustained closure rate for mucosal defects after C-ESD. The procedure
is simple and requires a short closure time, making it a useful method for defect
closure post-C-ESD. To the best of our knowledge, this study represents one of the
more extensive case series to date, examining 52 instances of mucosal defect closures
using the MANTIS Clip following C-ESD.
C-ESD poses unique challenges, primarily due to a higher frequency of perforation
compared with other organs [32]. This elevated risk highlights the critical need for reliable closure methods that
can effectively manage or prevent perforations. Effective colonic closure devices
must meet specific technical requirements: In the colon, particularly on the right
side, scope reinsertion can be troublesome and time-consuming, emphasizing the importance
of devices that can be easily inserted through the endoscopy channel. In addition,
these devices should be straightforward and quick to operate, reducing reliance on
scope maneuverability. Although delayed perforation after C-ESD is relatively rare,
its occurrence can be severe, often necessitating surgical intervention. Thus, the
ability of a closure device to perform prophylactic closures in high-risk scenarios
is particularly valuable, enhancing both safety and outcomes in C-ESD procedure.
The MANTIS Clip is a specialized device designed for the hold-and-drag closure technique
[13], which originally utilized only conventional reopenable clips. Conventional reopenable
clips often have blades that do not catch well, causing tissue to slip easily after
dragging and reopening. In contrast, the MANTIS Clip, with its mantis-like claw, ensures
strong tissue grasping and facilitates the hold-and-drag process. The median closure
time in this study was 8 minutes, which is comparable to the 8 to 18.2 minutes reported
in past studies of endoscopic closure methods utilizing endoclips, including the hold-and-drag
technique [11]
[13]
[15]
[16]
[18]
[19]
[20]. In addition, a unique aspect of this study is that all patients underwent second-look
endoscopy, revealing a sustained closure rate of 96.1% (49/51) among those who achieved
immediate closure post-ESD. Reports about sustained closure rates are limited, but
it has been reported as 64% (7/11) with the endoscopic hand-suturing technique [17] and 75% (3/4) with the Loop9 technique [18]. These findings demonstrate the robust closure force and durability of the MANTIS
Clip. This is particularly important in C-ESD, where the risk of delayed complications
such as perforation and bleeding could have serious consequences if closures are not
maintained. Ensuring durability of closure not only enhances patient safety but also
has the potential to reduce hospital stays, further emphasizing the clinical benefits
of a secure and reliable closure technique.
In the colon, closure should generally be performed along the longitudinal axis. Closing
along the short axis can reduce the working space, making subsequent clip placement
more challenging and increasing risk of stenosis in cases of large lesions. In the
application of the MANTIS Clip after C-ESD, we propose several best practices based
on our experiences, ensuring optimal outcomes through meticulous adherence to three
critical stages: anchoring, mobilization, and closure. First, it is essential to simulate
the hold-and-drag process to identify the optimal points for anchoring and closure.
We believe that for defects oriented along the axis of the colon, it is effective
to grasp the anal side of the edge and push toward the oral side. For a defect directly
facing the front, anchoring can be effectively performed from either the left or right
sides. During the anchoring phase, it is essential to capture as much tissue as possible,
aiming to grasp the mucosa, submucosa, and muscularis layers from above. This ensures
a stable base for manipulation and minimizes risk of tissue damage from the clip's
sharp blades. In the mobilization phase, carefully deflate the lumen to reduce tension
on the tissue and the clip. This step is crucial for minimizing risk of mechanical
stress and potential blade failure. Drag the clip with the endoscope toward the intended
optimal opposite target point to close. The clip should be slowly reopened after mobilization
to ensure the anchor does not slip, maintaining the integrity of the initial grasp.
Finally, during the closure phase, apply appropriate force to secure the tissue and
close the clip. The clip's release must be controlled to maintain proper alignment
and integrity of the tissue. This requires precision and a thorough understanding
of the device's mechanics to avoid premature closure or displacement of the clip.
By rigorously adhering to these practices, use of the MANTIS Clip can be optimized,
enhancing the safety and efficacy of C-ESD procedures and significantly reducing the
likelihood of complications.
Despite its benefits, the MANTIS Clip presents some challenges. Notably, excessive
tension can cause the arm to break when pressing the clip after reopening, a complication
we have encountered in our own experience. In addition, the sharpness of the clip's
claw poses a risk of accidentally damaging the exposed muscle layer, potentially leading
to perforation, necessitating careful handling, especially in narrow spaces. Furthermore,
the economic cost of the MANTIS Clip is a consideration. As of 2024, the retail price
is 15,000 JPY in Japan and $350 US dollars. In most C-ESD cases, a single MANTIS Clip
has been sufficient to approximate the center of the defect. Although SureClips were
used for additional clips in this study, non-reopenable conventional clips, which
are cheaper, can certainly serve as adequate substitutes, offering a more cost-effective
solution. Regardless, the MANTIS Clip is considered a clinically useful tool that
facilitates efficient and effective closure.
This study has several limitations including a small sample size and single-center,
retrospective design, which may affect generalizability of the results. The absence
of a control group limits comparative analyses with conventional closure methods,
and the observational nature of the study could introduce bias. In addition, variability
in operator skill with the MANTIS Clip could influence efficacy and safety results.
Because of these limitations, the results of our study should be interpreted with
caution. Future research should focus on larger, multicenter trials with randomized
controls to comprehensively evaluate clip effectiveness and safety across a broader
spectrum of lesion sizes and diverse clinical settings.
Conclusions
In conclusion, this study demonstrates the feasibility and efficacy of the MANTIS
Clip for mucosal defect closure following C-ESD. The results indicate a high success
rate and sustained effectiveness of closure, with minimal complications and brief
closure times. These findings suggest that the MANTIS Clip is a promising and efficient
tool for endoscopic closures after C-ESD. However, further studies are needed to confirm
these results and establish standardized protocols for its use in diverse clinical
environments.