Sinus Venosus Catheterization for Repeated Vascular Access in the Hybrid Striped Bass

Abstract

Placement of vascular cannulae for repeated venous blood sampling has proven to be a useful technique in many fish species. The anatomy and size of the hybrid striped bass (striped bass Morone saxatilis ♀ × M. chrysops ♂) makes this procedure challenging in this species. The sinus venosus was determined to be the best site for catheter placement based on size, accessibility, and ability to stabilize the catheter within it. Catheterization of the sinus venosus with a 20-gauge × 3.8-cm flexible Teflon catheter was unsuccessful because the catheter folded on itself, occluding the lumen. Catheterization with an 18-gauge × 3.8-cm hypodermic needle was also unsuccessful because the sinus wall occluded the needle lumen when negative pressure was applied. However, 18-gauge × 3.8-cm intravascular needles remained patent in free-swimming fish for 2 weeks without major complications. An external fixation device to prevent migration of the catheter out of the sinus venosus and laceration of the sinus wall during normal swimming movements improved the technique.