Portopulmonary venous anastomosis in balloon-occluded retrograde transvenous obliteration for the treatment of gastric varices

Background and Aim: Several reports have described portopulmonary venous anastomosis (PPVA). However, in balloon-occluded retrograde transvenous obliteration (BRTO), attention has not been paid to paradoxical embolism. The objective of this study was to investigate the existence of a right-left shunt due to PPVA when the drainage vein is occluded by a balloon during BRTO. Methods: The subjects were 19 patients who underwent BRTO. Whether PPVA was present was confirmed on balloon-occluded retrograde transvenous venography (BRTV). After BRTV, a retrograde bolus injection of 20 mL of carbon dioxide (CO2) via the balloon catheter was performed under balloon occlusion, and the flow of bubbles into both ventricles was observed with four-chamber view echocardiography. During the same balloon occlusion, bolus injection of CO2 into the inferior vena cava was performed, followed by echocardiography. Results: PPVA was confirmed on BRTV in four patients (21.1%). On echocardiography with retrograde CO2 injection, bubbles were confirmed in the left ventricle in six patients (31.6%). On echocardiography with CO2 injection into the inferior vena cava, bubbles were not confirmed in the left ventricle in any cases. Conclusions: When the draining vein was occluded with a balloon and blood flow in a gastrorenal or gastrocaval shunt was stopped during BRTO, PPVA was confirmed in 21.1% of cases on retrograde angiography, and a right-left shunt was confirmed in 31.6% of cases on echocardiography.