TY - JOUR
T1 - Does drainage hole size influence adhesion on ventricular catheters?
AU - Harris, Carolyn A.
AU - McAllister, James P.
PY - 2011/8
Y1 - 2011/8
N2 - Purpose: Ventricular catheter drainage holes of shunt systems used to treat hydrocephalus obstruct with tissue commonly comprising monocytes/macrophages, astrocytes, and giant cells. Despite high rates of obstruction, very few studies have manipulated drainage hole orientation, number, position, or diameter. By altering the hole diameter but maintaining a constant hole surface area, we manipulated shear stress through the holes, which we hypothesized would change the degree of macrophage and astrocyte attachment. Methods: First, a hole fabrication method was chosen from two fabrication techniques including punched holes in catheter tubing and constructed holes using nanofabrication techniques. Results: Punched holes were chosen to vary hole size from 282 to 975 μm because (1) samples were geometrically similar to commercially available ventricular catheters without significant microscopic differences in roughness values and (2) total macrophage and astrocyte adhesion on the punched holes was not significantly different from adhesion on the commercially available catheters. Overall adhesion from least to most adherent appeared to follow 975∈<∈754∈≈∈500∈<∈282-μm hole diameter for macrophages and 975∈<∈500∈<∈754∈<∈ 282 for astrocytes with an obvious dependency on catheter orientation with respect to the horizontal; a dependency to the proximity of the hole to the catheter tip was not observed. Conclusion: This study suggests that macrophage and astrocyte adhesion generally decreases with increasing hole diameter under flow conditions and underscores the necessity for future work to examine how hole diameter impacts inflammatory-based shunt obstruction.
AB - Purpose: Ventricular catheter drainage holes of shunt systems used to treat hydrocephalus obstruct with tissue commonly comprising monocytes/macrophages, astrocytes, and giant cells. Despite high rates of obstruction, very few studies have manipulated drainage hole orientation, number, position, or diameter. By altering the hole diameter but maintaining a constant hole surface area, we manipulated shear stress through the holes, which we hypothesized would change the degree of macrophage and astrocyte attachment. Methods: First, a hole fabrication method was chosen from two fabrication techniques including punched holes in catheter tubing and constructed holes using nanofabrication techniques. Results: Punched holes were chosen to vary hole size from 282 to 975 μm because (1) samples were geometrically similar to commercially available ventricular catheters without significant microscopic differences in roughness values and (2) total macrophage and astrocyte adhesion on the punched holes was not significantly different from adhesion on the commercially available catheters. Overall adhesion from least to most adherent appeared to follow 975∈<∈754∈≈∈500∈<∈282-μm hole diameter for macrophages and 975∈<∈500∈<∈754∈<∈ 282 for astrocytes with an obvious dependency on catheter orientation with respect to the horizontal; a dependency to the proximity of the hole to the catheter tip was not observed. Conclusion: This study suggests that macrophage and astrocyte adhesion generally decreases with increasing hole diameter under flow conditions and underscores the necessity for future work to examine how hole diameter impacts inflammatory-based shunt obstruction.
KW - Hole size
KW - Hydrocephalus
KW - Shear stress
KW - Shunting
UR - http://www.scopus.com/inward/record.url?scp=79960914794&partnerID=8YFLogxK
U2 - 10.1007/s00381-011-1430-0
DO - 10.1007/s00381-011-1430-0
M3 - Article
C2 - 21476036
AN - SCOPUS:79960914794
SN - 0256-7040
VL - 27
SP - 1221
EP - 1232
JO - Child's Nervous System
JF - Child's Nervous System
IS - 8
ER -