Shaheen Tabassum, Edirisinghe Thiaga, Gabriel Melissa, Bourdoumis Andreas, Buchholz Noor, Knight Martin
Endourology and Stone Services, The Royal London Hospital, Bartshealth NHS Trust, London, UK.
Urolithiasis. 2014 Jun;42(3):203-7. doi: 10.1007/s00240-014-0652-5. Epub 2014 Mar 18.
To measure and compare the percentage of surface and luminal thickness of encrustation in Allium and conventional double J ureteric stents after exposure for 6 weeks to an accelerated encrustation model.
An artificial urine solution was prepared and three stents were immersed into each of six containers allocated to each stent type, representing each week of encrustation. Slight agitation was accomplished by placing a magnetic stirrer at the bottom of each container. Images were obtained by examination under a stereomicroscope and analyzed with the aid of specialized image analysis software (Image J).
By week 2, nearly 100 % of the stent surface was covered by a thin layer of encrustation, gradually increasing in thickness through weeks 3-6. On completion of 6 weeks of encrustation, the 10 mm length double J stent specimens did not show visible encrustation, while the 60 mm long Allium stents showed 100 % surface coverage. This was most evident in the mid-section of the stents compared to the ends, suggesting a correlation between stent length and encrustation formation. There was also no blockage of the lumen of either stents between weeks 1-6.
The designed accelerated encrustation model was successful and showed 80 % surface coverage after 6 weeks. In our study, there appears to be a slightly reduced level of surface encrustation to that of earlier reports. A correlation between stent length and geometry was suggested. This model may be used to compare encrustation for a variety of polymeric stent materials.
在加速结石形成模型中，将葱状输尿管支架和传统双J输尿管支架暴露6周后，测量并比较其表面结石形成百分比和管腔结石厚度。
制备人工尿液溶液，将三种支架分别浸入分配给每种支架类型的六个容器中，每个容器代表结石形成的一周。通过在每个容器底部放置磁力搅拌器实现轻微搅拌。在体视显微镜下检查获取图像，并借助专业图像分析软件（Image J）进行分析。
到第2周时，几乎100%的支架表面被一层薄薄的结石覆盖，在第3至6周期间厚度逐渐增加。结石形成6周结束时，10毫米长的双J支架标本未显示出可见的结石，而60毫米长的葱状支架表面覆盖率为100%。与两端相比，这在支架的中部最为明显，表明支架长度与结石形成之间存在相关性。在第1至6周期间，两种支架的管腔均未堵塞。
所设计的加速结石形成模型是成功的，6周后表面覆盖率达80%。在我们的研究中，表面结石形成水平似乎比早期报告略有降低。提示支架长度与几何形状之间存在相关性。该模型可用于比较各种聚合物支架材料的结石形成情况。
