Clinical Trial Details
— Status: Enrolling by invitation
Administrative data
| NCT number |
NCT00680030 |
| Other study ID # |
EKSG 06/91 |
| Secondary ID |
|
| Status |
Enrolling by invitation |
| Phase |
N/A
|
| First received |
May 15, 2008 |
| Last updated |
May 15, 2008 |
| Start date |
September 2007 |
| Est. completion date |
December 2008 |
Study information
| Verified date |
May 2008 |
| Source |
Cantonal Hospital of St. Gallen |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
Switzerland: Ethikkommission |
| Study type |
Observational
|
Clinical Trial Summary
In the current study we plan to evaluate the effects of the conversion from gastric banding
to gastric bypass on esophageal function using combined monitoring. The primary aim of the
current study is to evaluate esophageal function before and 3-months after the conversion
from gastric banding to gastric bypass. A second objective is to evaluate the severity of
symptoms, esophageal dysmotilities, endoscopic abnormalities and bolus retention found in
patients referred for conversion from gastric banding to gastric bypass. Our hypothesis is
that esophageal motility disorders associated with gastric banding are reversed by
conversion to gastric bypass.
Description:
2.2.3 Research plan
As model for this study we propose a longitudinal single-center study design with testing
before and after the surgical intervention.
Participants
The study population will be limited to patients considered for gastric banding to gastric
by-pass conversion. Patients will be recruited from the surgical out-patient clinic
Testing during the study period
Pre-OP 3 months post-OP Symptom evaluation X X Endoscopy X X Upper GI series X X Combined
MII-EM X X
OP - conversion of gastric band to gastric bypass
After providing informed consent the volunteers will be screened for inclusion/exclusion
criteria. Participants fulfilling the inclusion/exclusion criteria will undergo baseline
symptom evaluation, endoscopy, an upper GI series and esophageal function testing using
combined MII-EM as part of the pre-operative work-up. The same examinations (symptom
evaluation, endoscopy, upper GI series and esophageal function testing) will be repeated 3
months after successful conversion from gastric band to bypass.
Symptom evaluation Patients will be asked to complete a standardized esophageal symptom
questionnaire. This questionnaire evaluates the frequency and severity of heartburn, chest
pain, regurgitation and dysphagia which are then computed into a composite score (Eraflux
score ).
Endoscopy Standard sedated endoscopy will be performed by a trained gastroenterologist. The
endoscopy will be performed according to the standard clinical protocol. During endoscopy
the examiner will pay particular attention to the esophageal mucosa, the size of the gastric
pouch above the band (baseline examination), the size of the gastric pouch above the
gastro-jejunal anastomosis (post-operative examination), the presence of ulcerations at the
site of gastric banding/gastric bypass.
Upper GI Series Patients will undergo upper GI series using a modified timed-barium swallow
(achalasia) protocol. Patients will receive 100ml liquid barium and PA images focused on the
GE junction will be taken immediately after swallowing, 1 and 3 minutes later. These
sequences should allow determining the position of the band relative to the GE junction and
the size of the gastric pouch above the gastro-jejunal anastomosis.
Esophageal function testing (EFT)
On the day of esophageal motility testing an EFT probe will be placed transnasally through
the esophagus into the stomach and the LES location and pressure will be determined by
stationary pull-through technique. The most distal circumferential pressure sensor will be
placed in the high-pressure zone (HPZ) of the LES. The other measuring sites (both pressure
and impedance) will be subsequently at 5, 10, 15 and 20 cm above the HPZ of the LES. Ten
swallows (5 cc each) of liquid (0.9% normal saline) and 10 swallows (5 cc each) of a
standard viscous material (EFT viscous, Sandhill Scientific, Inc) will be given with each
swallow 20-30 seconds apart.
Analyzed parameters:
- Bolus transit time (BTT): time interval (sec) between bolus entry at the proximal
measuring segment and bolus exit at the distal segment
- Smooth muscle bolus transit time (SMBTT): time interval (sec) between bolus entry at
the second most distal measuring segment and bolus exit at the distal segment
- Contraction amplitude at 5, 10, 15 and 20 cm above the HPZ
- Distal esophageal amplitude (DEA): average amplitude of contraction at 5 and 10cm above
HPZ
- Onset velocity of contractions: contraction velocity between 5 and 10 cm above the HPZ
- LES mid-respiratory resting pressure measured during station pull-through
- Average LES residual pressure during swallowing
Data analysis
Proportions (i.e. percentage of patients with esophageal dysmotility, patients with
ulcerations at the banding/anastomosis site, etc.) will be compared using McNemar test.
Continuous parameters (i.e. symptom scores, esophageal manometry and bolus transit data)
recorded prior and 3-months after the conversion will be compared using paired T-tests. For
statistical significance alpha will be set at 0.05.
Sample size calculation Assuming that esophageal dysmotilities are present in 50% of
patients prior to the conversion of banding to bypass and that conversion reduces this
proportion by 50% we calculated that 40 complete datasets would be required for an 85% power
to identify this change. Allowing a drop-out rate of 20% we plan to enroll 50 patients in
the present study.
