Limitations of Cyanoacrylate Injection for the Treatment of Gastric Fundic Varices: Reply to Matsumoto et al.

We are grateful to Dr. Matsumoto and his colleagues for their comments on our case report regarding a complication of endoscopic injection sclerotherapy for bleeding gastric varices. As we mentioned in the case report [1], the extravasation of sclerosant was caused by variceal rupture due to an abrupt increase in intravariceal pressure. The increase in pressure was caused by the additional injection of 2 ml of sclerosant, rather than by residual blood flow from the afferent vein of the gastric varix, as the blood flow ceases after the increase in intravariceal pressure, while the manual injection of sclerosant does not. In addition, a follow-up panendoscopy examination 28 months after the development of the complication showed complete eradication of the gastric varix, indicating that there had been no residual blood flow after the sclerotherapy.

Obliterating afferent veins and understanding the portal hemodynamics are helpful for predicting rebleeding of varices [2]. Endoscopic ultrasonography (EUS) has been found to be more sensitive than computed tomography (CT) in detecting paraesophageal varices [3]. EUS has also been shown to be highly sensitive in detecting gastric varices [4]. However, the patient in this case declined a further EUS examination after having an unpleasant experience with endoscopic sclerotherapy. In this type of situation, CT is still the best noninvasive method of assessing the extent of variceal eradication and any complications of endotherapy.

There is continuing debate regarding the ratio of cyanoacrylate to Lipiodol that should be used for endoscopic injection sclerosis. Reported ratios have ranged from 100 % to 25 %, without any significant increases in the complication rate due to systemic emboli or any reduction in the effectiveness of the procedure [5] [6] [7]. The varix treated in the case reported was a localized-type gastric varix with a diameter larger than 12 mm. We used a 1 : 1 mixture of cyanoacrylate and Lipiodol for sclerotherapy. Diluting the cyanoacrylate has the advantage that it makes injection easier and reduces the chances of the needle becoming occluded. As we previously reported, the risk of delayed polymerization and an increased risk of systemic embolization when using more diluted cyanoacrylate may be preventable if the cyanoacrylate is injected more slowly [8].

Balloon-occluded retrograde transvenous obliteration (BRTO) has been accepted in Japan as a minimally invasive and highly effective method of treating gastric varices. However, the success of BRTO requires familiarity with the hemodynamic features of the varices, including the anatomy of their afferent and efferent veins, which affect the degree of difficulty of the procedure [9]. As a large volume of ethanolamine is usually used in the BRTO procedure, common adverse effects including hemoglobinuria, abdominal pain, and low-grade fever have been reported. In addition, the procedure has also been associated with a few severe complications, such as cardiogenic shock, atrial fibrillation, and pulmonary embolism [10]. Endoscopic injection sclerotherapy has the advantages that it is easy to perform and that its effectiveness and safety have been confirmed. Although endoscopic injection sclerotherapy may fail to prevent recurrent bleeding from gastric varices, other modalities such as shunt surgery [11] or transjugular intrahepatic portal systemic shunting [12] have been successful and are used throughout the world. In the absence of evidence from controlled studies comparing the currently available methods of treating gastric varices, it is not yet possible to determine which method is superior or preferable to another.

References

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