Angulo Javier C, Gómez Reynaldo G, Nikolavsky Dmitriy
Departamento Clínico, Facultad de Ciencias Biomédicas, Hospital Universitario de Getafe, Universidad Europea de Madrid, Carretera de Toledo Km 12.5, 28905, Getafe, Madrid, Spain.
Hospital del Trabajador, Universidad Andrés Bello, Vicuña Mackenna, 185, Santiago, Chile.
Curr Urol Rep. 2018 Apr 11;19(6):37. doi: 10.1007/s11934-018-0786-z.
Due to the proximity of the rhabdosphincter and cavernous nerves to the membranous urethra, reconstruction of membranous urethral stricture implies a risk of urinary incontinence and erectile dysfunction. To avoid these complications, endoscopic management of membranous urethral strictures is traditionally favored, and bulboprostatic anastomosis is reserved as the main classical approach for open reconstruction of recalcitrant membranous urethral stricture. The preference for the anastomotic urethroplasty among reconstructive urologists is likely influenced by the familiarity and experience with trauma-related injuries. We review the literature focusing on the anatomy of membranous urethra and on the evolution of treatments for membranous urethral strictures.
Non-traumatic strictures affecting bulbomembranous urethra are typically sequelae of instrumentation, transurethral resection of the prostate, prostate cancer treatment, and pelvic irradiation. Being a different entity from trauma-related injuries where urethra is not in continuity, a new understanding of membranous urethral anatomy is necessary for the development of novel reconstruction techniques. Although efficacious and durable to achieve urethral patency, classical bulboprostatic anastomosis carries a risk of de-novo incontinence and impotence. Newer and relatively less invasive reconstructive alternatives include bulbar vessel-sparing intra-sphincteric bulboprostatic anastomosis and buccal mucosa graft augmented membranous urethroplasty techniques. The accumulated experience with these techniques is relatively scarce, but several published series present promising results. These approaches are especially indicated in patients with previous transurethral resection of the prostate in which sparing of rhabdosphincter and the cavernous nerves is important in attempt to preserve continence and potency. Additionally, introduction of buccal mucosa onlay grafts could be especially beneficial in radiation-induced strictures to avoid transection of the sphincter in continent patients, and to preserve the blood supply to the urethra for incontinent patients who will require artificial urinary sphincter placement. The evidence regarding erectile functional outcomes is less solid and this item should be furtherly investigated.
由于横纹括约肌和海绵体神经靠近膜性尿道，膜性尿道狭窄的重建存在尿失禁和勃起功能障碍的风险。为避免这些并发症，传统上倾向于采用内镜治疗膜性尿道狭窄，球部-前列腺吻合术则作为开放重建难治性膜性尿道狭窄的主要经典方法。重建泌尿外科医生对吻合性尿道成形术的偏好可能受创伤相关损伤的熟悉程度和经验影响。我们回顾文献，重点关注膜性尿道的解剖结构以及膜性尿道狭窄治疗方法的演变。
影响球部-膜性尿道的非创伤性狭窄通常是器械操作、经尿道前列腺切除术、前列腺癌治疗及盆腔放疗的后遗症。作为与尿道不连续的创伤相关损伤不同的实体，为开发新的重建技术，需要对膜性尿道解剖结构有新的认识。尽管经典的球部-前列腺吻合术在实现尿道通畅方面有效且持久，但存在新发尿失禁和阳痿的风险。更新且侵入性相对较小的重建替代方法包括保留球部血管的括约肌内球部-前列腺吻合术和颊黏膜移植增强膜性尿道成形术。这些技术积累的经验相对较少，但一些已发表的系列研究呈现出有前景的结果。这些方法尤其适用于既往行经尿道前列腺切除术的患者，在试图保留控尿和勃起功能时，保留横纹括约肌和海绵体神经很重要。此外，对于放射性狭窄患者，引入颊黏膜覆盖移植可能特别有益，对于仍有控尿能力的患者可避免横断括约肌，对于需要植入人工尿道括约肌的尿失禁患者可保留尿道血供。关于勃起功能结果的证据尚不确凿，这一问题应进一步研究。
