Balloon-occluded retrograde transvenous obliteration (B-RTO) has been widely accepted as an effective treatment for gastric varices caused by portal hypertension. With this method, there are two main situations in which use of a micro-balloon catheter is useful. One is gastric varix without gastro-renal shunt for which B-RTO was performed through the pericardiacophrenic vein or inferior phrenic vein. The other is when gastric varix with gastro-renal shunt and communication between gastric varices and systemic vein is also developing, in which case double balloon technique is performed in B-RTO. Paralleling the development of micro-balloon catheters, opportunities to use this device would increase in B-RTO procedure.
Transarterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) has been performed for more than 30 years. Now, TACE is the most used treatment for unresectable HCC with proven improvement in survival in selected patients. Conventional TACE (cTACE) which has been performed using Lipiodol (LPD) emulsion mixed with anticancer drugs followed by porous gelatin sponge particles has been a mainstream in Japan. Dense LPD accumulation after cTACE is one of the significant prognostic factors affecting local recurrence. Recently, microballoon catheters have been introduced to clinical practice in Japan. Irie et al. noted balloon-occluded TACE (B-TACE) induced dense LPD accumulation in HCC. B-TACE has become rapidly popular in the past several years in Japan since there were reports that B-TACE has the potential to improve cancer nodule control locally, compared with cTACE. However, further prospective studies are needed to prove the efficacy of B-TACE. All microballoon catheters which are an essential device in B-TACE have been developed in Japan. Here, we describe the transition of microballoon catheters and the current status of B-TACE.
NBCA has been reported as an effective embolic agent but there are some drawbacks to control the embolic range. Some techniques such as “Wedge injection” have been advocated to overcome these drawbacks but the optimal techniques have been not confirmed. Therefore, the safety and effectiveness of embolization depend on the operator’s ability and experience. We advocated the new NBCA injection technique named “B-glue” which is the NBCA injection during a vascular occlusion with a recently developed microballoon catheter. The purpose of this review is to describe the methods, characteristics, limitations and future of B-glue, based on the reported animal experiments and case reports. Further evaluation such as optimal NBCA-lipiodol dilution ratio and waiting time between NBCA injection and balloon deflation is necessary. It has been also uncertain whether B-glue can be applied for larger vessels or complex vascular network. Moreover, uncertainty of a potential risk of stronger adhesion to the vascular wall remains because balloon structures have a larger surface.
LOGOSSWITCH® is a newly developed microballoon catheter with side hole system which has the new concept of ‘distal blockage’. This ‘distal blockage’ means the cessation of the distal vessel flow by balloon inflation to avoid non-target embolization when we inject drugs into the proximal vessel branches that are too tiny to advance the microcatheter into. LOGOSSWITCH® has good availability for conventional angiographic catheters (less than 0.038 inch inner diameter, 2.0 Fr tip size and 2.8 Fr shaft size), almost adequate size of the balloon (3-6 mm in diameter), ability of the power injection of the contrast without balloon inflation, and good microcatheter performance such as good selectivity and good maneuverability. LOGOSSWITCH® would be very useful when difficult cases to perform selective intervention are encountered. But hemodynamic changes during the balloon inflation must be monitored carefully.
We describe the methods, recommended indications for, and latest opinions of microballoon catheter assisted coil embolization. Microballoon catheter assist should be considered, when the parent artery is large and the blood flow is rapid, active bleeding is found, or prevention of coil protrusion or short distance embolization is necessary. There are 3 techniques: proximal balloon inflation technique (proximal BT), distal balloon inflation technique (distal BT), and double balloon inflation technique (double BT).