Guiffant Gérard, Flaud Patrice, Royon Laurent, Burnet Espérie, Merckx Jacques
University Paris Diderot, Biofluidic Group, UMR CNRS.
Pulmonary Department and Adult Cystic Fibrosis Centre, Cochin Hospital.
Med Devices (Auckl). 2017 Jan 17;10:11-15. doi: 10.2147/MDER.S125605. eCollection 2017.
Three types of totally implantable venous access devices, Ports, are currently in use: titanium, plastic (polyoxymethylene, POM), and mixed (titanium base with a POM shell). Physics theory suggests that the interaction between a non-coring needle (NCN, made of stainless steel) and a plastic base would lead to the stronger material (steel) altering the more malleable material (plastic).
To investigate whether needle impacts can alter a plastic base's surface, thus potentially reducing flushing efficacy.
A Port made of POM was punctured 200 times with a 19-gauge NCN. Following the existing guidelines, the needle tip pricked the base with each puncture. The Port's base was then examined using a two-dimensional optical instrument, and a bi-dimensional numerical simulation using COMSOL was performed to investigate potential surface irregularities and their impact on fluid flow.
Each needle impact created a hole (mean depth, 0.12 mm) with a small bump beside it (mean height, 0.02 mm) the Reynolds number Re≈10. A numerical simulation of the one hole/bump set showed that the flushing efficacy was 60% that of flushing along a flat surface.
In clinical practice, the number of times a Port is punctured depends on patient and treatment characteristics, but each needle impact on the plastic base may increase the risk of decreased flushing effectiveness. Therefore, the more a plastic Port is accessed, the greater the risk of microorganisms, blood products, and medication accumulation.
Multiple needle impacts created an irregular surface on the Port's base, which decreased flushing efficacy. Clinical investigation is needed to determine whether plastic base Ports are associated with an increased risk of Port infection and occlusion compared to titanium base Ports.
目前有三种类型的完全植入式静脉通路装置，即输液港，正在使用：钛质、塑料（聚甲醛，POM）和混合型（钛基座配POM外壳）。物理理论表明，非切割针（NCN，由不锈钢制成）与塑料基座之间的相互作用会导致更坚硬的材料（钢）改变更具延展性的材料（塑料）。
研究针刺是否会改变塑料基座的表面，从而可能降低冲洗效果。
用19号非切割针对一个由聚甲醛制成的输液港进行200次穿刺。按照现有指南，每次穿刺时针尖刺入基座。然后使用二维光学仪器检查输液港的基座，并使用COMSOL进行二维数值模拟，以研究潜在的表面不规则性及其对流体流动的影响。
每次针刺都会产生一个孔（平均深度为0.12毫米），旁边有一个小凸起（平均高度为0.02毫米），雷诺数Re≈10。对一个孔/凸起组的数值模拟表明，冲洗效果是沿平坦表面冲洗效果的60%。
在临床实践中，输液港的穿刺次数取决于患者和治疗特点，但每次针刺塑料基座都可能增加冲洗效果降低的风险。因此，塑料输液港使用得越多，微生物、血液制品和药物积聚的风险就越大。
多次针刺在输液港基座上形成了不规则表面，降低了冲洗效果。需要进行临床研究，以确定与钛基座输液港相比，塑料基座输液港是否与输液港感染和堵塞风险增加有关。
