Department of Urology, St. Marianna University School of Medicine, Kawasaki, 216-8511, Japan.
J Pediatr Surg. 2010 Dec;45(12):2423-30. doi: 10.1016/j.jpedsurg.2010.08.047.
Lower urinary tract obstruction causes both renal failure and bladder dysfunction after birth. This study examined the early bladder wall changes after creating an obstructive uropathy focusing on bladder wall thickness and muscle integrity.
We created obstructive uropathy in fetal lambs at 60 days' gestation, ligating the urethra and urachus. The fetuses (n = 28) were delivered at 48 hours and 3, 4, 5, 7, and 14 days after obstruction and at term (145 days' gestation). Sham-operated lambs were used as controls (n = 20). Histology samples were stained using α-smooth muscle actin) immunohistochemistry and also hematoxylin-eosin, Masson trichrome, and colloidal Fe stain.
The bladder wall initially expanded and stretched. By day 4, the bladder wall became thicker. Histologically, the bladder in obstructed lambs demonstrated a prominent submucosal fibrotic change by 7 days. The mean bladder wall thickness at 14 days after obstruction was thicker than controls, and fibrosis was prominent.
The initial changes in the bladder wall were expansion of the muscle component followed by fibrosis. The bladder wall thickness dramatically increased 4 to 7 days after obstruction. We conclude that shunting operations to preserve bladder function may be needed earlier than expected.
下尿路梗阻可导致出生后肾功能衰竭和膀胱功能障碍。本研究通过检测膀胱壁厚度和肌肉完整性，观察梗阻性尿路后早期膀胱壁的变化。
我们在胎羊妊娠 60 天时通过结扎尿道和脐尿管来建立梗阻性尿路模型。在梗阻后 48 小时以及 3、4、5、7 和 14 天以及足月（妊娠 145 天）时剖宫取出胎儿（n=28），同时以假手术胎羊作为对照（n=20）。使用α-平滑肌肌动蛋白免疫组化以及苏木精-伊红、马松三色和胶体铁染色对组织学样本进行染色。
膀胱壁最初扩张和拉伸。到第 4 天，膀胱壁变得更厚。组织学上，梗阻组羔羊的膀胱在第 7 天就表现出明显的黏膜下纤维化改变。梗阻后 14 天的膀胱壁厚度平均值大于对照组，且纤维化明显。
膀胱壁的初始变化是肌肉成分的扩张，随后是纤维化。梗阻后 4 至 7 天，膀胱壁厚度急剧增加。我们得出的结论是，为了保留膀胱功能，分流手术可能需要比预期更早进行。
