Introduction
Available devices and accessories for performing Per oral endoscopic myotomy (POEM)
are sometimes technically challenging and require constant exchange for dissection
and spot coagulation, resulting in prolonged procedural time with an acceptable risk
of complications [1]
[2]. Speedboat-RS2 (Creo-Medical, UK) is an endoscopic device that has been utilized
for submucosal dissection of esophageal, gastric, and colonic lesions [3]. The device delivers bipolar radiofrequency energy (BRF) for dissection and cutting
and microwave energy through its tip [4]. The integrated retractable injection needle is used for mucosal incision and submucosal
lift, hence no instrument change is required. The CROMA generator is used to supply
microwaves to ablate and coagulate. BRF is used for precise lateral and forward cutting
[4]. Microwave coagulation helps to achieve controlled hemostasis, the heat-insulated
hull reduces risk of muscle damage, and the optimized shaft design helps in controlled
rotation. The combination of these features results in quicker procedures with good
precision. The feasibility of this device for POEM is currently unexplored. We review
our experience with initial two cases of POEM by using Speedboat-RS2 in patients with
achalasia.
Methods
This was a retrospective review of two patients who underwent POEM by using Speedboat-RS2 at
a tertiary care referral center. The study conformed to the ethical guidelines of
the 1975 Declaration of Helsinki (7th revision, 2013). The conduct of this study was
approved by the Institutional Ethics Committee. Waiver of consent was obtained for
the study. Both patients were adults and had previously given their written informed
consent for the procedure.
The demographic details, procedural indications, clinical and physical findings of
patients were extracted from their case records. Patients were kept nil per os for
12 hours prior to endoscopy. Proton pump inhibitors (PPIs), antiemetics, broad-spectrum
antibiotics, and premorbid medications (wherever appropriate) were administered an
hour prior to the intervention. Two operators performed one procedure each. General
anesthesia was used in both patients and the procedure was performed [5] with the patients in supine position.
We used a high-definition endoscope Evis Exera II GIF-2TH180 gastrovideoscope (Olympus,
United States). A retractable integrated needle was used for submucosal injection.
After instillation of a mixture of 0.9 % normal saline with 0.3 % indigo carmine,
a mucosal incision was made with the edge of the device using BRF. This was made along
the 2 o’clock for anterior in the first case and 5 o’clock for posterior wall of the
esophagus in the second case, 15 cm above the gastroesophageal junction (GEJ). The
submucosal plane was entered and a submucosal tunnel was created (BRF, cutting frequency
400 kHz, power setting 35 W) by using Speedboat-RS2 for 2 cm beyond the GEJ. The endoscope
was withdrawn into the esophageal lumen and entered the stomach, where a bluish submucosal
hue in a retroflexed view confirmed the adequacy of the tunnel. This step was repeated
(if necessary) while dissecting beyond the GEJ. The Sppedboat-RS2’s novel design provided
lateral and/or forward cutting using the curved tip, flat edges of the blade. Microwave
coagulation (frequency 5.8 GHz, power setting 10 W) was used to achieve controlled
hemostasis. Larger vessels were pre-coagulated with microwave power for 5 to 10 seconds.
An insulated “hull” remained parallel to the muscle layer and there was no mucosal
injury. The insulated hull is rotatable and can be oriented upside down. About 9 cm
of the circular and longitudinal muscle fibers of the esophagus were cut effortlessly
and a complete myotomy was performed 2 cm beyond the GEJ. The esophageal lumen was
inspected for any mucosal break. The mucosal incision was finally closed with endoscopic
clips (Instinct endoscopic hemoclip, Cook Medical, Bloomington, Indiana, United States
([Fig. 1a–i] and [Video 1]). Patients were kept NPO for 24 hours and then discharged.
Fig. 1
a Speedboat RS2 Endoscopic device with attached blade, insulated hull, and needle.
b Retractable integrated needle being used for submucosal injection. c Instillation of saline underneath mucosa. d An incision being made on posterior wall of the esophagus. e Submucosal tunnel being created using Speedboat-RS2. f Lateral and forward cutting of circular and longitudinal muscle fibers of the esophagus
using the curved tip and flat edges of the blade. g Lateral and forward cutting of circular and longitudinal muscle fibers of the esophagus
using the curved tip and flat edges of the blade. h Lateral and forward cutting of circular and longitudinal muscle fibers of the esophagus
using the curved tip and flat edges of the blade. i Mucosal incision closed with standard hemoclips.
Video 1 Endoscopic video showing peroral endoscopic myotomy being performed with Speedboat
RS2.
Results
Two patients (both males) with a mean age of 46 years and mean symptom duration of
3 years were included. Both patients had type II achalasia cardia diagnosed on high-resolution
manometry (HRM) (Trace 1.2.3a V software, Royal Melbourne Hospital, Australia). One
patient underwent anterior myotomy and the other posterior approach. Submucosal tunneling
(~15 cm) was achieved in a mean of 20 minutes, and ~9 cm myotomy in 8 minutes and
the entire procedure was completed in a mean of 30 minutes with 100 % technical success
([Table 1]). Both patients were discharged the day after the procedure without any immediate
complications. Both patients were tolerating soft diet, so they were advised to transition
to solid food. At 6-week follow-up, both patients were asymptomatic, able to swallow
solid food without difficulty, and underwent upper gastroscopy, which was uneventful.
Table 1
Characteristics of patients undergoing POEM with Speedboat-RS2.
|
Variables
|
Case 1
|
Case 2
|
|
Age/gender
|
53/male
|
39/male
|
|
Duration of symptoms (years)
|
2.5
|
3.5
|
|
High resolution manometry findings
|
Type II–achalasia
|
Type II–achalasia
|
|
Myotomy approach
|
Anterior
|
Posterior
|
|
Submucosal tunneling time (min)
|
22
|
18
|
|
Myotomy time (min)
|
8
|
8
|
|
Total procedure time (min)
|
32
|
28
|
|
Technical success
|
Achieved
|
Achieved
|
|
Adverse events
|
Nil
|
Nil
|
|
Follow-up endoscopy
|
Normal
|
Normal
|
POEM, peroral endoscopic myotomy
Discussion
We used the Speedboat-RS2 to perform POEM in two patients and a good response was
seen. We used different a myotomy approach in each patient. That was done to compare
differences in length of time for the procedures. Both procedures were safely done
in an endoscopy suite and the patients did not have any complications. We found that
the device helps to reduce overall procedure time as we did not change the device
for bleeding vessels which normally require a coagulation grasper.
Prior to the advent of the Speedboat-RS2, POEM could be performed with standard techniques
in about 40 minutes. The main advantages of the device are reduced risk of injury
to mucosa by orientation of the hull and use of BRF, which aids quick tissue healing,
thereby resulting in quicker post-procedural recovery and time savings. The true benefit
of using this device is that it makes life much easier during submucosal tunneling
which is a crucial step in POEM. With its sophisticated design, the Speedboard-RS2
cuts in forward, lateral, and oblique planes using bipolar RF 400KHz cutting and provides
hemostasis with microwave coagulation (5.8GHz). To the best of our knowledge, this
is the first case report of use of the SpeedboatRS2 for POEM in the world and the
first use of such a device in the Asia-Pacific region for third space endoscopy. The
device has already met with success in en-bloc gastric/esophageal mucosal resection
[6]
[7]. Although the economics of it currently remain unexplored, the device certainly
looks to make a huge impact in terms of its advantages over currently existing standard
accessories in POEM. Our center has been performing POEM for almost a decade and diverticular
POEM [8], and the advent of Speedboat-RS2 has certainly opened up new avenues in third space
endoscopy [9].
Although POEM has been practiced for more than a decade, major bleeding, pneumothorax,
mucosal perforation, and post procedural infections still are routinely encountered.
Although in the majority of cases, these complications can be tackled in the same
sitting, some patients need repeated interventions so as to prevent future complications.
This leads to patient dissatisfaction with the procedure. We feel the advanced technology
of the Speedboat RS2 overcomes many of the problems faced in routine third space procedures.
Bipolar devices are specialized, with a range of outputs and modes for various applications,
especially in elderly patients with cardiac conditions [10]. Speedboat-RS2 has recently received approval from the US Food and Drug Administration
for use in minimally invasive removal of bowel lesions. The device may be of vital
use in various minimally invasive surgical procedures [11]. While performing the procedure, we used a 2TH endoscope, since the Speedboat-RS2
needs a wider therapeutic channel (3.7 mm), however, the procedure can even be performed
with a 1TH endoscope from Olympus. The latter was currently unavailable to us, hence
we proceeded with the former. We did not encounter any flexibility issues when using
a larger scope and POEM was performed in both patients meticulously and with ease.
Cutting of tissue and coagulating small vessels traditionally has been achieved by
using monopolar current (high voltage 2000V) which has potential for resulting in
deep burns causing mucosal perforation. The Speedboat-RS2, in contrast, uses bipolar
RF (low voltage 200V) for large vessels, which is associated with minimal risk of
deep burns and helps with rapid tissue healing [6]
[10]. The device is boat-shaped and has curved bipolar electrodes on the sides. When
current flows through the tissue between the two electrodes, the cutting effect is
restricted to the needle electrode. When an incision is made, tissue damage is restricted
to this small region. The power requirements are lower because the current is limited
to the small piece of tissue between the active electrodes, which results in more
predictable tissue modification [10]. Although utmost care is required when using the Speedboat-RS2 in a confined space,
potential for alternative site burns is minimal. BRF indeed provides multiple advantages
compared to stand-alone injection needles and cutting devices, but there exists an
unmet need for future comparative studies with the hybrid knife device, which also
can be used to inject and dissect. The latter uses a water jet for rapid submucosal
infusion of saline solution while tunneling, eliminating the need for repeated changes
of equipment. However, in the event of bleeding from larger vessels, especially at
GEJ, coagrasper hemostatic forceps are required to achieve hemostasis. With the Speedboat
device, hemostasis can be achieved with the same device because uses microwave coagulation
and controlled hemostasis. It also limits the depth of injury. Doctors undergoing
training or fellowship will find it much easier to use Speedboat RS2 for third space
endoscopy as the device may reduce the overall risk and potential complications associated
with these procedures. The small sample size is a limitation of our study, however,
looking at the promising results with the device, we believe such anecdotal innovative
cases lay a platform for developing future studies.
Conclusion
To conclude, early experience shows that use of the Speedboat-RS2 to perform POEM
is feasible and it has a good safety profile and precision. Submucosal tunneling with
the device was done relatively quickly and coagulation was effective. Long-term studies
with a larger patient cohort are warranted.
