Development of gastric fundal varices is an important manifestation of portal hypertension. Gastric fundal varices most frequently result from generalised or segmental (portal or splenic vein thrombosis) portal hypertension9
and the development of gastric fundal varices may depend on the pre-existing venous anatomy in the gastric fundus. The exact incidence of fundal varices is unknown.
As with other portosystemic collaterals anywhere in the abdomen, variceal bleeding is the most life threatening complication of gastric and especially fundal varices, with a mortality rate of up to 30% at bleeding.24
Compared with oesophageal variceal bleeding, haemorrhage from fundal varices is more severe and is associated with significantly higher blood transfusion requirements.24
From a clinical point of view, it is essential to recognise that only fundal varices that are located within the gastric wall (that is, submucosal location) may haemorrhage.8,9
In contrast, fundal varices that are located along the outside border of the gastric fundal wall (that is, perigastric/adventitial varices) do not.
The diagnosis of fundal varices, in particular of submucosal fundal varices, is challenging. Using endoscopy, submucosal fundal varices often appear as mass-like nodular and tortuous winding elevations of the mucosa in the fundus.18
Due to their deep submucosal location as well as the normal colour and appearance of the overlaying mucosa, it may be difficult to distinguish fundal varices from gastric folds, particularly in the presence of hypertensive gastropathy.5,7,8,10,18
Moreover, the red colour signs seen on oesophageal varices are rarely seen over fundal varices.18
EUS is currently considered the most useful modality for assessment of fundal varices by its ability to demonstrate the different layers of the gastric fundus. This allows for precise information with regard to the presence, size, and exact location of the varix within the gastric fundus (that is, submucosal versus perigastric location of fundal varices).5,7,8,10
However, a broad use of EUS is hampered by its limited availability in relatively few specialised centres,25
as well as its operator dependency, with only a fair interobserver agreement with regard to assessment of vascular lesions in the stomach.25
On double contrast barium studies, the appearance of fundal varices may be confused with a tumorous lesion.9,27
Splenoportography and direct transhepatic portography allow excellent delineation of the portal and splenic venous system and its collateral circulation. The main limitation of angiography is its inability to determine the relationship of the vessels to the mucosa.9,14
Contrast enhanced conventional and single detector helical CT as well as MR imaging are useful modalities for expeditiously evaluating the overall status of portosystemic vessels in patients with portal hypertension.9,11–13
However, to the best of our knowledge, no attempt has been made to evaluate if CT or MR imaging might provide information on fundal varices, in particular with regard to the relationship between the varix and the mucosa. With the advent of MDCT technology, CT angiography has been improved substantially by offering shorter acquisition times, increased volume coverage, lower dose of contrast medium, and improved spatial resolution for assessing small visceral vessels.15,17
In this prospective study, we investigated the clinical applicability of MDCT angiography in the diagnosis of submucosal and perigastric fundal varices. The high reliability and robustness of MDCT angiography was reflected in the overall good to excellent image quality and high interobserver agreements between all three readers in the diagnosis of submucosal and perigastric varices, as well as assessments of variceal size and location. This imaging technique for detection of fundal varices does not differ substantially from imaging protocols that are currently used for MDCT angiography. The main difference is oral ingestion of plain water to distend the stomach and gastric fundus, which is essential for distinction between submucosal and perigastric fundal varices. MDCT scanners are currently widely available throughout the entire world and in our experience reading of these cases does not require a long learning curve.
Compared with EUS, a high correlation was obtained by all three independent readers who evaluated the MDCT angiograms for the presence of submucosal and perigastric fundal varices. Only in one patient was there a disagreement between EUS and MDCT angiography in the detection of a small (<5 mm in diameter) submucosal fundal varix. It is of interest to emphasise that based on MDCT angiography, all three readers noted that a submucosal varix was probably or definitively present (scores 4 and 5). In a repeated EUS, which was performed later and which was not part of the study protocol, the presence of a submucosal varix was confirmed in this patient. Hence it may be hypothesised that the diagnostic performance of MDCT angiography in the detection of submucosal fundal varices exceeds that of EUS. However, this hypothesis needs to be validated in a larger group of patients.
In this study, we demonstrated that MDCT angiography was capable of differentiating between submucosal and perigastric fundal varices which is of paramount clinical interest. MDCT angiography may also be useful for assessment of the therapeutic effect of endoscopic sclerotherapy of fundal varices. In our series, MDCT angiography demonstrated residual submucosal fundal varices in all patients who had a history of prior endoscopic sclerotherapy. In addition, MDCT angiography allows identification of the afferent and efferent veins of fundal varices. This may be of clinical and therapeutic relevance with regard to planning of alternative therapeutic strategies such as balloon occluded retrograde transvenous obliteration of gastric varices.28
An important drawback of MDCT angiography for imaging fundal varices is the applied radiation dose inherent in this technique. In our study, an effective dose of 4–5 mSv was calculated for both men and women. In addition, intravenous application of iodinated contrast medium may be contraindicated in patients with renal insufficiency. This is even more important in patients with end stage liver cirrhosis as those patients often suffer from additional renal insufficiency.29
Furthermore, treatment of fundal varices cannot be followed immediately in the same session after diagnosis of submucosal fundal varices on MDCT angiography. These drawbacks may hamper its routine use in patients with suspected fundal varices and may justify its indication in clinical situations when EUS may be not available or is contradicted (for example, in patients with large oesophageal varices or after ligation therapy of oesophageal varices).
The following limitations of the study need to be addressed. As only patients with suspected fundal varices on oesophagogastroduodenoscopy and no control group were included in our study, this may have resulted in inclusion bias. Another important limitation is the lack of a true diagnostic standard of reference for the presence of submucosal and perigastric fundal varices, such as a pathological correlation in all patients. In addition, a small number of patients were included in our study group. Clearly, more data are needed to determine if MDCT angiography is useful as a screening tool for detection of submucosal fundal varices in patients with portal hypertension. Finally, we did not evaluate the impact of MDCT angiography on treatment of gastric fundal varices. The optimal therapy of bleeding gastric fundal varices (for example, sclerosing therapy, ligation therapy, TIPSS, balloon occluded retrograde transvenous obliteration, or surgery) as well as the question of prevention and the effect of oesophageal variceal eradication on gastric fundal varices have not yet been determined.24
Future prospective studies are warranted to evaluate whether diagnosis and classification of submucosal fundal varices by MDCT angiography influences the decision making of gastroenterologists treating patients with gastric fundal varices.
In conclusion, this study has demonstrated for the first time that MDCT angiography is equivalent to EUS in the detection and characterisation of fundal varices, in particular with regard to the distinction between submucosal and perigastric fundal varices. MDCT angiography may become an important supplemental or alternative technique in clinical situations when EUS is not available or is contradicted.