Peroral endoscopic myotomy (POEM) vs endoscopic balloon dilation (EBD) for the treatment of achalasia in children

Achalasia is a rare motility disorder of the esophagus that is characterized by
aperistalsis of the oesophageal body and dysrelaxation of the lower
oesophageal sphincter. Achalasia is caused by progressive destruction and
degeneration of the neurons in the myenteric plexus. This leads to subsequent
retention of food and saliva in the oesophagus, resulting in the typical
symptoms of achalasia such as dysphagia, chest pain, regurgitation of
undigested food and weight loss. Treatment of achalasia is focused on symptom
relief, which is obtained by destroying the occluding function of the spastic
lower oesophageal sphincter. Treatment options are endoscopic dilatation by a
pneumatic balloon, the golden standard, or Heller myotomie a surgical treatment
performed by laparoscopy. Endoscopic pneumodilatation can be complicated by a
perforation and there is a relative high chance of symptom recurrence which
requires subsequent treatment sessions. The surgical treatment can also be
associated with severe complications, like a perforation, and is more invasive.
Currently endoscopic pneumodilatation is the first choice of treatment in
patients with achalasia and surgical myotomy is generally performed in case of
symptom recurrence after initial pneumodilatation. The recent developments on
minimal invasive surgical techniques has led to the development of per-oral
endoscopic submucosal myotomy (POEM) for the treatment of achalasia. The first
results of the POEM are very positive and suggest that this treatment is better
than the endoscopic pneumodilation.

To compare the efficacy of POEM to the efficacy of endoscopic pneumodilatation
as initial treatment of symptomatic idiopathic achalasia in children. The
primary outcome measure is the need of retreatment (i.e. EBD, LHM, POEM or
intra-sphincteric botox injection) due to persisting symptoms (Eckardt score >
3) with evidence of recurrence on barium swallow and/or HRM at 12 months
follow-up.

Multicenter randomized clinical trial.

Study subjects undergo a POEM or endoscopic pneumodilatation

Per-oral endoscopic submucosal myotomy (POEM): The POEM technique is entirely
endoscopic. Using an endoscopic knife, an entry to the submucosal space is made
in the oesophagus and after creating a submucosal tunnel towards the lower
oesophageal sphincter the circular muscle layers are cut. At the end of the
procedure the mucosal opening is closed with clips.

Endoscopic pneumodilatation: Endoscopic dilatation of the lower oesophageal
sphincter is first performed by a Rigiflex balloon of 30mm and a second
dilatation is performed two weeks later with a Rigiflex balloon of 35mm. A
third dilatation is performed if the Eckardt symptomscore is above 3, within 6
months after the first dilatation or if barium esophagram and/or HRM are
suggestive for relapse.

For this study patients with achalasie will be treated with per-oral endoscopic
myotomy (POEM) or endoscopic pneumodilatation Both procedures are associated
with risks, including a bleeding during or after treatment, a perforation of
the oesopahgus or stomach during the treatment and an infection after
treatment. These complications can be solved during the endoscopy in most
cases. Refer to protocol 9.4 for more details.

To determine effectiveness, patients are followed for a period of 1 year.
Patients need to fill out questionnaires at 3 and 6 month post-operative and at
1 year follow-up. Furthermore they need to undergo a gastroscopy, a timed
barium oesophagogram, high resolution manometry and a 24 hour pH-impedance
monitoring. The barium-esophagram is the only invasive investigation duringe
follow up, that is not performed during standard clinical care, yet is needed
to evaluate treatment efficacy. After initial procedure study subjects need to
visit the outpatient clinic three times for follow-up.

The first results of the POEM are very promising and suggest that this
treatment is better than the endoscopic pneumodilation, the gold standard.
The risks of both procedures are likely very similar. Furthermore patients that
are not participating in the trial will undergo a treatment anyway, in most
cases this will be endoscopic pneumodilatation.