Transradial artery cannulation is a useful alternative approach to the performance of diagnostic and interventional coronary procedures. However, its utility can be limited by incomplete palmar collateral support, access site failure, and anatomic variations. We report on five patients in whom percutaneous cannulation of the ulnar artery was primarily chosen, based on preprocedure examination, for coronary angiography in three patients and percutaneous coronary intervention in two others. The transulnar artery approach to coronary procedures is feasible and may be preferable in selected cases. Anatomic considerations are discussed.

Details are presented of two patients with end-stage renal disease (ESRD) who recently experienced migration of a Viabahn covered stent from a peripheral hemodialysis A-V access to the right lower lobe pulmonary artery. Successful percutaneous retrieval was achieved in one patient using a dual snare approach, facilitated by ex vivo product testing. The second patient was managed conservatively. A review of the institution's A-V access salvage procedures, indicated a concomitant trend toward greater use of stent-assisted procedures, and a higher utilization of covered versus uncovered stents.

We used direct invasive techniques to measure the effects of hyperventilation on the pulmonary blood flow (Q) and on recirculation time of helium and of carbon dioxide in humans. The subjects hyperventilated with a tidal volume of 1.5 liters (BTPS) and a frequency of 20 or 30 breaths/min. There was no significant change in Q from control at either level of hyperventilation. Helium first appeared in the pulmonary artery within 12 s from the onset of hyperventilation and increased by approximately 0.7% of its equilibrium arterial value per second at both levels of hyperventilation. In contrast, the PVCO2 remained at base-line level until 43 s from the onset of hyperventilation. We conclude that hyperventilation at 30 or 45 l/min with constant tidal volume does not significantly affect the value of Q and that the amount of recirculation of the two gases does not result in underestimation of Q when this variable is measured by indirect respiratory rebreathing techniques.

No abstract