Case report
A 59-year-old-male underwent an endoscopic mucosal resection (EMR) of a 4-cm cecum
polyp 1 year earlier. At that time, the patient had three endo-clips placed to close
the EMR defect that was created. The pathology from the EMR was a tubulovillous adenoma.
The patient was lost to follow-up but returned 1 year later for endoscopic follow-up. At
the site, a previously placed endoclip was present, with residual polyp tissue embedded
at the site. Attempted removal of the clip by an experienced senior gastroenterologist
with a snare was unsuccessful. Biopsy of the polyp showed high-grade dysplasia.
The patient refused surgery and thus a repeat colonoscopy was performed by an interventional
endoscopist. The clip was in place and residual neoplasia was seen in the cecum ([Fig. 1a ]). Repeat attempts by two advanced endoscopists to remove the clip using a snare
and grasper were unsuccessful, as the clip was deeply embedded in the tissue. The
polyp was injected but a submucosal lift could not be obtained. Snare cautery removal
was not attempted for fear of possible perforation because thermal injury to the cecum
wall was a possibility. The decision was made to perform salvage nitrous oxide balloon-based
cryotherapy (C2 Therapeutics, Redwood City, California, United States). It is non-thermal
and the balloon self-vents excess gas to avoid perforation.
Fig. 1 a Residual polyp from a prior endoscopic mucosal resection, seen embedded within an
endoclip at the cecum. b Balloon-based cryotherapy being performed as a salvage technique to ablate the residual
neoplasia. The yellow arrow is pointing to the endoclip.
A therapeutic gastroscope was used for the procedure. The CryoBalloon was able to
appose the residual polyp and clip. A dosimetry of 10 seconds was used to ablate the
residual neoplasia ([Fig. 1b ]). Immediately after the cryotherapy, the area was erythematous consistent with post-ablation
effects ([Fig. 2a ]). On 2-month follow-up, the cecum was free of the polyp and clip ([Fig. 2b ]). There was a subtle scar that could be seen ([Fig. 2b ], blue arrows). The clip had previously been in place for 1 year and could not be
removed by multiple endoscopists. However, the CryoBalloon ablation was successful
in removing the clip and eradicating the residual neoplasia. Biopsies of the scar
were negative for residual polyp tissue.
Fig. 2 a Residual neoplasia site post cryotherapy. b Follow-up colonoscopy 2 months after cryotherapy showing the cecum is free of polyp
and the endo-clip. The arrows point to the subtle scar at the prior polyp site.
Discussion
This case shows that cryotherapy can be used to ablate unwanted tissue in the colon.
The vast majority of the literature for use of the CryoBalloon has been for ablation
of unwanted esophageal tissue, specifically Barrett’s esophagus and esophageal squamous
dysplasia. A multicenter, prospective non-randomized trial of 39 patients with Barrett’s
esophagus dysplasia showed the device was feasible and safe [1 ]. In a different prospective trial, 41 patients (22 treatmen- naïve) with Barrett’s
esophagus dysplasia were treated with the CryoBalloon [2 ]. At 1 year, rates of complete eradication of dysplasia and intestinal metaplasia
rates were 95 % and 88 %, respectively. A multicenter trial currently of more than
100 treatment-naïve patients with Barrett’s esophagus dysplasia who underwent CryoBalloon
therapy currently is nearing completion.
The CryoBalloon has also been evaluated for treatment of esophageal squamous neoplasia.
In a retrospective study of 10 patients, the device was used for ablation [3 ]. At 3 months follow-up, complete eradication was observed in all patients. Results
from a large Asian prospective trial are anticipated in manuscript form soon. The
abstract presented at Digestive Disease Week 2018 showed the CryoBalloon was well
tolerated and highly effective [4 ].
The CryoBallon has been used outside the esophagus in the stomach for ablation of
gastric antral vascular ectasia (GAVE) [5 ]. In a multicenter retrospective study of 23 patients with GAVE refractory to argon
plasma coagulation, the CryoBalloon was highly effective [6 ]. At 6 months, 83 % of patients were transfusion-independent and 87 % had more than
75 % of the GAVE successfully eradicated.
This is the first report of use of the CryoBalloon in the colon. The main limitation
of this case is that usually endoclips can be easily removed, and this was the reason
for the difficulty in eradicating the residual neoplasia. However, this clip was unusual
in that it remained for more than a year and thus was likely deeply embedded. In addition
a senior gastroenterologist and two additional interventional endoscopists could not
remove this clip despite exhaustive attempts.
It should be noted that the CryoBalloon can only be used with a therapeutic gastroscope,
which limits its applications in the colon. However in our experience, especially
with difficult colonoscopy, the vast majority of the colon can be examined with a
gastroscope [7 ]. Large feasibility and safety studies are needed prior to endorsing its routine
use in the colon. However, this case shows that this is a viable salvage technique
for use in the colon when standard techniques fail.
