Shaul D B, Xie H W, Diaz J F, Mahnovski V, Hardy B E
Department of Urology, Children's Hospital Los Angeles and the University of Southern California, USA.
J Pediatr Surg. 1996 Feb;31(2):225-8. doi: 10.1016/s0022-3468(96)90002-0.
As an alternative to bladder mucosa, free grafts of tubularized peritoneum were used as urethral substitutes in a rabbit model of hypospadias. In group 1, six mature rabbits underwent partial penile urethrectomy followed by interposition of a 2-cm-long peritoneal-lined tube graft. These animals had urethrograms performed at 3 months and were killed at 6 (n = 4) or 12 (n = 2) months. In group 2, six rabbits underwent total penile urethrectomy with placement of 3-cm-long grafts. These animals were killed 1 to 4 weeks after surgery. Clinical assessment and gross examination of the 12 rabbits showed no urinary retention, two small fistulas at the proximal anastomosis, and no strictures or diverticular. At 6 and 12 months (group 1) the urethra had healed completely and the graft edges were not visible. In group 2, 1 to 4 weeks after surgery the graft was intact and the interface between the graft and native urethra was visible. Histological studies of the grafts were compared with control peritoneum. At 1 week, a high-density single-cell layer was present. Beginning at 2 weeks, a multilayered epithelium was present, which became more organized in the older grafts. Neovascularity became visible in the subepithelial layer at 2 weeks. Acute inflammatory cells were present early and were replaced by a palisading layer of lymphocytes and plasma cells in the older grafts. Minimal fibrosis was observed. Tubularized peritoneal free grafts are a promising new urethral substitute. Graft placement is technically simple. Replacement of the peritoneum by a multilayered epithelium resembling transitional epithelium occurs early after graft placement. As much as 1 year later, minimal scarring is present.
作为膀胱黏膜的替代物，在尿道下裂兔模型中，将管状腹膜游离移植物用作尿道替代物。在第1组中，6只成年兔接受部分阴茎尿道切除术，随后置入一段2厘米长的带腹膜内衬的管状移植物。这些动物在3个月时进行尿道造影，并在6个月（n = 4）或12个月（n = 2）时处死。在第2组中，6只兔接受全阴茎尿道切除术并置入3厘米长的移植物。这些动物在术后1至4周处死。对这12只兔的临床评估和大体检查显示无尿潴留，近端吻合处有两个小瘘管，无狭窄或憩室。在6个月和12个月时（第1组），尿道已完全愈合，移植物边缘不可见。在第2组中，术后1至4周移植物完整，移植物与天然尿道之间的界面可见。将移植物的组织学研究与对照腹膜进行比较。在1周时，存在高密度的单细胞层。从2周开始，出现多层上皮，在较老的移植物中变得更加有组织。在2周时，上皮下层可见新生血管。早期存在急性炎性细胞，在较老的移植物中被淋巴细胞和浆细胞的栅栏状层所取代。观察到最小程度的纤维化。管状腹膜游离移植物是一种有前景的新型尿道替代物。移植物置入在技术上很简单。移植物置入后早期，腹膜被类似于移行上皮的多层上皮所替代。长达1年后，瘢痕形成最小。
