Method for Blind Catheter Placement in the Equine Pulmonary Artery

The navigation behavior of catheters within the equine pulmonary artery (PA) was investigated using en bloc heart and lung preparations for the purpose of developing a method of blind catheter placement. An equine ex vivo heart and lung perfusion system with controlled perfusate pulsatile flow, pressure, and temperature was used to evaluate a blind navigation technique for placement of balloon-tipped catheters into the distal main stem of the PA. Catheter performance was observed with an intravascular endoscope. Three balloon catheters were selected for navigation trials: a 4 mm diameter × 1.2 cm, 2.7Fr, 142 cm angioplasty catheter (C4mm); a 10 mm diameter × 4 cm, 5Fr, 150-cm angioplasty catheter (C10mm); and a 16-mm diameter, 7Fr, 200-cm pancreatic duct sphincteroplasty catheter (C16mm). Successful catheter placement was defined as insertion within a left or right main stem of the PA to a distance greater than 20 cm beyond the bifurcation. A method of blind catheter placement into the distal main stem of the equine PA using balloon-tipped catheters was successfully developed. The 16-mm catheter was superior with an average proportion of successful insertions (PSIavg) of 93.6%; an average insertion distance in the main stem (IDMavg) of 30.1 ± 5.7 cm; and an average insertion distance anywhere in the PA (IDAavg) of 29.3 ± 6.4 cm versus the 10 mm (PSIavg 25%, IDMavg 39.3 ± 11.4 cm, IDAavg 19.3 ± 15.1 cm) and 4 mm (PSIavg 11%, IDMavg 40.0 ± 11.0 cm, IDAavg 12.8 ± 13.2 cm), respectively.