A new device for full-thickness colorectal resection, the so-called full-thickness
resection device (FTRD; Ovesco Endoscopy, Tübingen, Germany) has been available since
November of 2014. It is the first commercial system based on the over-the-scope clip
(OTSC) principle. The FTRD consists of a modified 14 t OTSC mounted on a transparent
cap, which has a monofilament polypectomy snare preloaded on its tip. The FTRD can
be mounted over a standard colonoscope [1]. Because the volume of the transparent FTRD cap is greater than that of the OTSC
cap (3 cm3 vs. 0.9 cm3), full-thickness specimens with a median resection surface of 5 cm2 (range 1.6 cm2 – 12.9 cm2) can be obtained [2].
A 59-year old patient was referred for further treatment after incomplete polypectomy
of a large rectal polyp. Histologically, a tubulovillous adenoma harboring high grade
dysplasia was described. The index endoscopic procedure demonstrated a villous polyp
in the rectosigmoid curve that was difficult to visualize. With a mounted transparent
distance cap (MAJ-663; Olympus, Tokyo, Japan), better visualization was possible,
and a large, broad-based villous polyp remnant about 3 cm in diameter was seen ([Fig. 1]).
Fig. 1 Flexible endoscopy in a 59-year old woman referred for further treatment after incomplete
polypectomy of a large rectal polyp, described as a tubulovillous adenoma harboring
high grade dysplasia. a With a standard colonoscope, only part of the polyp remnant is visible. b Visualization of the true extent of the polyp remnant is improved with the mounted
distance cap.
After the patient had provided informed consent, polypectomy of the polyp remnant
was performed close to its base with a standard snare (FlexSnare; Medwork, Höchstadt/Aisch,
Germany; [Fig. 2]). Then, the FTRD was mounted on a colonoscope (CF-H180AI, Olympus), and a full-thickness
resection of the entire polypectomy site was carried out uneventfully ([Fig. 3]). The snare polypectomy remnant and the FTRD specimen measured 3 × 2 × 1 cm and
3.1 × 2.5 × 0.8 cm, respectively ([Fig. 4]). The entire procedure is presented in [Video 1].
Fig. 2 Endoscopic view of the polyp base after snare resection. The lateral margins of small
polyp remnants (asterisks) have been marked with the coagulation probe (arrows) included
in the package of the full-thickness resection device.
Fig. 3 Resection with the full-thickness resection device (FTRD). a The polypectomy site with visible small remnants of the polyp is pulled into the FTRD
cap with the grasper (asterisk) included in the package. The polypectomy snare is
preloaded on the FTRD cap (cross), and an over-the-scope clip (OTSC; arrow) is also
loaded on the FTRD cap. b Full-thickness resection site with the OTSC in situ.
Fig. 4 The full-thickness resection specimen includes the R2 margin of the snare polypectomy.
Based on the histological examination result, R0 resection was achieved.
Resection of a large rectal polyp with the simultaneous combination of snare polypectomy
and full-thickness resection device resection.
Histological examination confirmed full-thickness resection. The polyp remnant contained
low grade dysplasia, and the FTRD remnant contained parts of the tubulovillous adenoma
with negative resection margins. At follow-up 8 weeks later, the OTSC had detached
spontaneously. A normal scar with some granulation tissue (typical after FTRD resection)
was seen ([Fig. 5]).
Fig. 5 Scar at 8 weeks after resection with the full-thickness resection device (FTRD).
The clip has detached spontaneously. There is some granulation tissue in the center
of the scar, typically seen early after FTRD resection.
To our knowledge, this is the first report of simultaneous snare polypectomy and FTRD
resection. The volume of the polyp was too large for FTRD resection alone, and it
would not have fit into the FTRD cap. After the snare resection, clearly no R0 resection
had been obtained. We decided on the simultaneous snare polypectomy and FTRD resection
in order to avoid scarring and the development of tissue fibrosis. For successful
FTRD resections comparable to OTSC treatment [3], tissue mobilization into the FTRD cap is crucial. At a later time, this might be
complicated or even prevented by the healing process after the resection of a large
polyp [1]
[2]
[3].
In conclusion, if incomplete snare polypectomy can be expected, additional resection
of the polyp base remnant with the FTRD in the same session may be reasonable. Informed
consent should be obtained before the procedure, and the necessary materials must
be available.
Endoscopy_UCTN_Code_TTT_1AQ_2AD
