In clinical practice, we have summarized that the radial pulses of patients with radial puncture failure are more likely to be weak, while ulnar pulses at the same side are relatively strong. For those patients with wide diameters, strong beat and easy punctured ulnar artery, is it suitable for them to go through transulnar access? We referred to Chinese forearm arterial anatomic data and found that, just like dominance of left and right coronary artery, there also exists dominance between radial and ulnar artery. The diameter of ulnar artery in Chinese male is around 2.5–2.8 mm, and that of radial artery in female is 2.3–2.5 mm. Both sides are nearly the same and the right size of dextromanual patients is slightly wider than left. Therefore, no matter male or female, if a patient’s ulnar artery diameters is above 2.3 mm, he can be operated with 6Fr guiding catheter (inner diameter 2 mm). Puncture needles, expanding sheath and operation equipment in transradial access operation are also suitable in transulnar intervention, which lays the foundation for transulnar access in anatomy and interventional equipment. Meanwhile, experts in hand surgery pointed out that since hand is supplied by bilateral blood circulation, puncturing ulnar artery and inserting sheath and catheter are safe, which do not affect hand function. However, since ulnar artery stretches closely to ulnar nerve, operators should pay attention to nerve damage.

Therefore, two main reasons have been considered for the choice of ulnar arterial approach. Firstly, when radial artery is contraindicated or unsuccessful as well as avoidance of the femoral arterial access, ulnar arterial access should be considered. Secondly, sometimes radial artery may be selected as the potential harvest for coronary bypass graft. For protection of the hand, safe ulnar arterial access remains predicated on the integrity of the palmar collaterals.

The ulnar artery puncture and cannulation is similar to the way of radial artery. The right forearm was abducted and placed on a rest attached to the catheterization table, with hyperextention of the wrist. After local subcutaneous anesthesia with 1 % lidocaine, the skin was infiltrated over the palpable artery at the site where the pulsation was the strongest, usually 1–5 cm proximal from the pisiform bone (ulnar artery), and 1–5 cm proximal from the styloid process (radial artery). The anterior wall of the artery was punctured using a 21 gauge needle. After the puncture, a 0.5334 mm (0.021 in.) guidewire was inserted (Cordis Corporation, Florida, USA). A short 4-French or 6-French tapering introducer (Cordis Corporation) was placed on the 0.5334 mm (0.021 in.) wire through a skin incision made by cutting gently with a surgical knife. A bolus of 3000 U unfractionated heparin and 200 μg of nitroglycerin were administrated to the access artery through the sheath catheter. In patients undergoing percutaneous coronary intervention (PCI), weight-adjusted unfractionated heparin (100 U/kg) was administrated through the sheath catheter to achieve and maintain an activated clotting time between 250 and 350 s. A 7-French introducer over a 0.038 in. wire was substituted for the 4-French or 6-French sheath catheter when a 7-French guiding catheter was needed in the procedure (Fig. 9.2). 4-French Judkins diagnostic catheters (Terumo, Tokyo, Japan) or 5-French TIG diagnostic catheters (Terumo) were used for diagnostic coronary angiography. Angioplasty was done with 6-French guiding catheters having an inner diameter of 1.8034 mm (0.071 in.) or 1.778 mm (0.070 in.) (Medtronic, Danvers, MA or Cordis Corporation) or 7-French guiding catheters having an inner diameter of 2.0574 mm (0.081 in.) (Medtronic). The catheters were advanced over a standard 0.035 in. spring guidewire. Commercially available guidewires for percutaneous transluminal coronary angioplasty (PTCA), rapid-exchange balloons, and balloon-expandable stents were used according to standard procedures. Forearm artery angiography was performed at the end of procedure before sheath removal, which was used to evaluate the anatomical variations of the forearm artery. The sheaths were immediately withdrawn after the procedure and a hemostasis strap over a gauze was applied to compress the puncture site for 4–6 h, followed by a non-occlusive pressure dressing.

Subsequently, we started to propagandize and popularize TUI in many domestic conferences of cardiovascular disease, and gradually expanded its clinical PCI field including multi-vessel lesion, CTO lesion, in-stent restenosis, even AMI fit for TUI. It was found that TUI was similar to TRI in the door to balloon time and each procedural time, which suggested that for the patient with ulnar artery superiority, TUI could be not only used in common PCI, but in AMI-PCI as the superior or alternative vessel. Thus, almost all of AMI patients were fit for PCI via transforearm (radial/ulnar) artery, and the success rate of PCI was increased, while crossover to TFI was unnecessary. So far, many interventional cardiologists have tried to use ulnar artery as an alternative artery for PCI in lots of hospitals across the country. In 2004, I was invited to carry out TUI for over hundreds of German patients in St. Elizabeth Heart Center. We reported < Feasibility of percutaneous coronary intervention via transulnar artery approach in patients with coronary heart disease > in the largest conference all over the world–TCT 2014, while the operation photo was published in <American Journal of Cardiology> (Fig. 9.3).