OBJECTIVE: Cardiologists use the distal radial artery (dRA) approach in daily clinical practice. This method is gradually being applied in neuroendovascular treatment. However, limited studies have been reported concerning tumor embolization using small-bore guidance via dRA. CASE PRESENTATION: Five consecutive tumoral cases underwent endovascular embolization via the dRA approach. The right dRA was punctured, with manual confirmation of pulsation or under the guidance of ultrasonography, using a 22-G plastic cannulation needle. After the insertion of a 0.021-inch guidewire, a dilator of a 4-Fr sheath enlarged the puncture site. The 22-G plastic cannulation needle was replaced with an 18-G cannulation needle, and a 0.035 guidewire was inserted to introduce a small-bore guide. A TEMPO4 (Cordis, Miami Lakes, FL, USA
outer diameter: 1.35 mm) or a 3.6-Fr JB2 (Gadelius Medical, Tokyo, Japan
outer diameter: 1.2 mm) was used in 4 cases to convey embolization materials, whereas a 4-Fr, 16-cm sheath (Terumo, Tokyo, Japan
outer diameter: 2 mm) combined with a 4-Fr SY3 (Gadelius Medical
outer diameter: 1.4 mm) was used in 1 case. Trisacryl gelatin microspheres or CONCLUSION: Tumor embolization using small-bore guide via the dRA approach was completed without any complications.