Abstract
Objective Efficient flow of fluids through drainage/infusion catheters is affected by surrounding
tissue, organ compression, and scar tissue development, limiting or completely obstructing
flow through drainage holes. In this work, we introduce a novel three-dimensional
(3D) drainage catheter with protected side holes to reduce flow blockages. We then
compare its drainage performance to standard straight and pigtail catheters using
computer-generated catheter designs and flow analysis software.
Methods Drainage performance was computed as flow rate through the catheter for a given pressure
differential. Each catheter contained drainage holes on the distal (insertion) end
and a single outlet (hub) hole open to atmosphere. Computational fluid dynamics using
ANSYS AIM 18.2 was used to simulate flow through the catheter and examine drainage
performance based on variations to the following parameters: (1) side hole shape,
(2) cross-sectional area of the catheters, (3) number of side holes, and (4) cross-sectional
area of the side holes.
Results Drainage through the newly introduced catheter in all simulations was nearly identical
to standard pigtail and straight catheters. While working to optimize the 3D catheter
design, we found that the changes in side hole shape and side hole cross-sectional
area had little effect on the total flow rate through the catheters but had a large
impact on flow rate through the side hole nearest to the hub (proximal hole). Additionally,
the majority of flow in all catheters occurred at the most proximal 1 to 3 side holes
closest to hub, with relatively little flow occurring at side holes more distally
located (closest to insertion end). The 3D catheter demonstrated no changes in flow
characteristics when the coiled segment was occluded, giving it an advantage over
other catheter types when the catheter is compressed by surrounding tissue or other
external obstruction.
Conclusions The majority of fluid flow in catheters with a diameter of 4.67 mm (14 Fr) or smaller
occurred at the most proximal 1 to 3 side holes. A novel 3D coiled catheter design
can protect these proximal holes from external blockage while maintaining drainage
performance compared with standard straight and pigtail catheters.
Keywords
catheter occlusion - innovation and design - suction catheter
