Soria F, Morcillo E, López de Alda A, Pastor T, Sánchez-Margallo F M
Unidad de Endoscopia de la Fundación Centro de Cirugía de Mínima Invasión Jesús Usón. Cáceres. España.
Servicio de Urología. Hospital Don Benito-Villanueva. Badajoz. España.
Arch Esp Urol. 2016 Oct;69(8):553-564.
One of the main wishes in the field of urinary catheters and stents is to arm them with biodegradable characteristics because we consider a failure of these devices the need for retrieval, the forgotten catheter syndrome as well as the adverse effects permanent devices cause after fulfilling their aim. The efforts focused in new designs, coatings and biomaterials aim to increase the biocompatibility of theses internal devices. Lately, there have been correct advances to answer the main challenges regarding biodegradable ureteral devices. Thus, modulation of the rate of degradation has been achieved thanks to new biomaterials and the use of copolymers that enable to choose the time of permanence as it is programmed with conventional double J catheters. Biocompatibility has improved with the use of new polymers that adapt better to the urine. Finally, one of the main problems is elimination of degraded fragments and experimentally it has be demonstrated that new designs elicit controlled degradation, from distal to proximal; using stranding and combination of copolymers degradation may be caused by dilution, reducing fragmentation to the last stages of life of the prosthesis. Moreover, it has been demonstrated that biodegradable catheters potentially may cause less urinary tract infection, less encrustation and predictably they will diminish catheter morbidity, since their degradation process reduces adverse effects. Regarding the development of biodegradable urethral stents, it is necessary to find biomaterials that enable maintaining their biomechanical properties in the long term, keeping open the urethral lumen both in patients with BPH and urethral stenosis. Modulation of the time of degradation of the prosthesis has been achieved, but the appearance of urothelial hyperplasia is still a constant in the initial phases after implantation. The development of drug eluting stents, anti-proliferative or anti-inflammatory, as well as biodegradable stents biocoated is a field from which it is expected the arrival of the solution of theses adverse effects. Therefore, many features need to be improved to obtain biodegradable stents, but over the last years some turning points have been accomplished thanks to the advances in Bioengineering, allowing to foresee safe and effective solutions in the nearest future.
在导尿管和支架领域，一个主要愿望是赋予它们可生物降解的特性，因为我们认为这些装置出现故障时需要取出，存在导尿管遗忘综合征，以及永久性装置在达到其目的后会产生不良影响。致力于新设计、涂层和生物材料的努力旨在提高这些体内装置的生物相容性。最近，在应对可生物降解输尿管装置的主要挑战方面取得了一些正确进展。因此，由于新型生物材料以及共聚物的使用，降解速率得到了调节，这使得能够像传统双J导管那样设定留置时间。通过使用更能适应尿液的新型聚合物，生物相容性得到了改善。最后，一个主要问题是降解碎片的清除，实验表明新设计可引发从远端到近端的可控降解；通过绞合和共聚物组合，降解可能由稀释引起，从而减少假体使用寿命最后阶段的碎片。此外，已经证明可生物降解导管可能导致更少的尿路感染、更少的结垢，并且可以预见它们将降低导管发病率，因为其降解过程减少了不良影响。关于可生物降解尿道支架的开发，有必要找到能够长期保持其生物力学性能、在良性前列腺增生症患者和尿道狭窄患者中都能保持尿道腔通畅的生物材料。假体降解时间的调节已经实现，但植入后初始阶段尿路上皮增生的出现仍然是一个常见现象。药物洗脱支架、抗增殖或抗炎支架以及生物涂层可生物降解支架的开发是有望解决这些不良影响的一个领域。因此，要获得可生物降解支架，许多特性需要改进，但在过去几年中，由于生物工程学的进展，已经取得了一些转折点，从而有望在不久的将来找到安全有效的解决方案。
