Al-Rifaei M A, Zaghloul S, Al-Rifaei A M
Department of Urology and Anatomy, Faculty of Medicine, University of Alexandria, Alexandria, Egypt.
Scand J Urol Nephrol. 2005;39(2):163-8. doi: 10.1080/00365590310019972.
OBJECTIVE. To identify the precise anatomy of the membranous and bulbous urethrae and their relation to the neurovascular bundles (cavernous nerves and vessels). Based on the findings, a modified surgical technique was developed to preserve potency by avoiding injury to the neurovascular bundles during surgery on the posterior urethra.
The material for this study consisted of 10 male cadavers. We injected eight cadavers with a mixture of red latex and lead oxide. By means of meticulous dissection we removed the bladder, prostate, urethra, penis, surrounding vessels and nerves. We also identified the anatomical relations between various urogenital structures and the vessels and nerves. We examined the specimens radiologically. In the other two cadavers, we removed the membranous urethrae and subjected them to histological examination. We used haematoxylin-eosin and Verhoeff von Gieson stains to study the elastic tissues.
The membranous urethra measured 2.5-3 cm in length. It originated from the lower third of the anterior surface of the prostate (and not from the apex) as a continuation of the prostatic urethra. The wall of the membranous urethra contained abundant elastic fibres. The neurovascular bundles were located posterolateral to the mid-portion of the prostate and prostatic apex. Near the apex the neurovascular bundle divided into two parts: a larger anterior part and a smaller posterior part. The anterior part crossed the membranous urethra, then the bulb of the penis at the 1 and 11 o'clock positions and finally entered the corpus cavernosum. The posterior part crossed the membranous urethra more posteriorly to enter the bulb of the penis. Between 1992 and 2003 we managed 22 patients (age range 16-50 years) with posterior urethral obstruction secondary to pelvic fracture by means of bulboprostatic anastomosis. We managed 17 patients via the perineal route and five via a combined perineoabdominal-transpubic route. All of these patients were potent before the operation, which proved the integrity of the neurovascular bundles. We could spare the anterior divisions of the neurovascular bundles (greater cavernous nerves and vessels) during their crossing of the bulb of the penis by cutting and dissecting within the bulb (not outside it) before dismembering it from the urogenital diaphragm. We also refrained from any dissection of the apex and the posterolateral surfaces of the prostate to avoid injury to the neurovascular bundles. At 6-year follow-up (range 1-10 years) 21/22 patients preserved their potency, giving a success rate of 95.45%. Of the 22 patients, two became temporarily impotent after the operation but regained potency within a period of 4-6 months.
Our technique of neurovascular bundle preservation during bulboprostatic anastomotic urethroplasty may solve the problem of postoperative impotence.
目的。确定膜性尿道和球部尿道的精确解剖结构及其与神经血管束（海绵体神经和血管）的关系。基于这些发现，开发了一种改良手术技术，以在尿道后段手术中避免损伤神经血管束，从而保留性功能。
本研究的材料包括10具男性尸体。我们向8具尸体注射了红色乳胶和氧化铅的混合物。通过细致的解剖，我们移除了膀胱、前列腺、尿道、阴茎、周围的血管和神经。我们还确定了各种泌尿生殖结构与血管和神经之间的解剖关系。我们对标本进行了放射学检查。在另外两具尸体中，我们移除了膜性尿道并进行了组织学检查。我们使用苏木精-伊红染色和韦尔霍夫-冯·吉森染色来研究弹性组织。
膜性尿道长度为2.5 - 3厘米。它起自前列腺前表面的下三分之一（而非顶端），是前列腺尿道的延续。膜性尿道壁含有丰富的弹性纤维。神经血管束位于前列腺中部和前列腺尖的后外侧。在前列腺尖附近，神经血管束分为两部分：较大的前部和较小的后部。前部穿过膜性尿道，然后在阴茎球部的1点和11点位置穿过阴茎球，最后进入海绵体。后部在更靠后的位置穿过膜性尿道进入阴茎球。1992年至2003年期间，我们通过球部前列腺吻合术治疗了22例（年龄范围16 - 50岁）因骨盆骨折导致后尿道梗阻的患者。我们通过会阴途径治疗了17例患者，通过会阴-腹部-耻骨联合联合途径治疗了5例患者。所有这些患者在手术前性功能正常，这证明了神经血管束的完整性。在将阴茎球从泌尿生殖膈分离之前，我们可以通过在阴茎球内部（而非外部）切割和解剖，在神经血管束穿过阴茎球时保留其前部（较大的海绵体神经和血管）。我们也避免对前列腺尖和后外侧表面进行任何解剖，以避免损伤神经血管束。在6年随访（范围1 - 10年）中，22例患者中有21例保留了性功能，成功率为95.45%。在这22例患者中，有2例术后暂时出现性功能障碍，但在4 - 6个月内恢复了性功能。
我们在球部前列腺吻合尿道成形术中保留神经血管束的技术可能解决术后性功能障碍的问题。
