43% of the fluoroscopic studies agreed with the OGD.
Of these 19 were normal studies. 10 contrast studies had additional findings to those on OGD and 36 contrast swallows did not correlate with OGD.
A note here is that 27 of these found dysmotility,
something that is not well assessed on OGD (see below).
Within our populations a total of 27 hiatus hernias were identified,
12 cases were present on both studies,
but 15 were present only on one study.
Both OGD and contrast swallow identify hiatus hernias,
however they can be present on one and not the other due to their dynamic nature (1).
This shows that both investigations are useful in the diagnosis of hiatus hernias.
Reflux was more frequently diagnosed in this study on OGD rather than contrast swallow due to the ancillary signs of reflux oesophagitis being present on endoscopy.
Reflux is only usually demonstrated in a third of cases on a contrast swallow study,
with variable techniques used by radiologists to provoke this.
24 hour pH monitoring is a more robust way of detecting this (2).
Oesophageal dysmotility is commonly seen in patients with reflux oesophagitis (3). Within our data set dysmotility is mostly present on fluoroscopy (27 cases) and not OGD (1 case).
This is logical as the ‘real time’ illustration of oesophageal motility can be captured on contrast swallow.
One third of the contrast swallows that identified dysmotility had abnormalities on the OGD.
It has been shown that mucosal changes such as oesophagitis are often present alongside dysmotility (4).
This shows the importance of considering OGD findings when approaching a contrast swallow.
are mostly found in the upper oesophagus and can be treated with dilatation if symptomatic.
In this study none of the webs identified with contrast swallow were seen on OGD. These findings in the upper oesophagus emphasise the importance of evaluating this area with the contrast swallow as small webs can be easily missed on endoscopy.
The above is also true for pouches.
However often this pathology has a different diagnostic pathway; a contrast swallow will be requested before an OGD due to the risk of OGD mistaking a pouch for the true lumen and potentially increasing the risk of oesophageal perforation if unrecognised.
For this study we used the clinical details provided on the contrast swallow request from CRIS to identify abnormalities seen on OGD.
the contrast swallow findings should have been correlated with the official OGD report on the hospital database.
Therefore we may not have identified all patients who had an OGD as this may not have been recorded on CRIS.
additional findings such as oesophagitis,
and candida were only visible on OGD,
as at our institution only single contrast views of the oesophagus are obtained thus limiting evaluation of the oeesophageal mucosa.
Overall fluoroscopy proves its utility in the diagnosis of upper gastrointestinal pathologies,
not only in identifying motility disorders but pathologies such as webs,
pouches and hiatus hernias which sometimes cannot be seen on OGD.
Therefore the full contrast swallow should be performed to include the upper oesophagus.
Contrast swallow is not an investigation to replace OGD as the visualisation of the mucosal surfaces is better on endoscopy; however it is a useful adjunct to OGD in recognising additional pathologies.
The results of any prior OGD should be considered before a contrast swallow study is performed,
as any mucosal abnormalities seen on endoscopy may predispose patients to further abnormalities such as dysmotility.