Kaefer M, Peters C A, Retik A B, Benacerraf B B
Division of Urology, Children's Hospital, Boston, Massachusetts, USA.
J Urol. 1997 Sep;158(3 Pt 2):1026-9.
The combination of in utero bladder distension and bilateral hydroureteronephrosis in male fetuses may result from a number of pathological processes. The prenatal and postnatal treatment of patients with an enlarged bladder is dictated by the specific etiology leading to these changes. We propose specific ultrasonographic criteria for differentiating between obstructive and nonobstructive etiologies in these fetuses.
We reviewed the medical records and prenatal imaging studies of 18 cases of marked in utero bladder distension in which a diagnosis of posterior urethral valves, the megacystis-megaureter association or the prune-belly syndrome was confirmed postnatally. Amniotic fluid volume and renal echogenicity were assessed before knowledge of the specific diagnosis. Oligohydramnios was graded as mild, moderate or severe. Increased renal echogenicity was defined as greater echogenicity of the renal cortex and/or medulla than of adjacent liver tissue. Postnatal imaging, clinical course and outcome were also reviewed.
The study included 15 cases with adequate followup, including 8 in which a diagnosis of posterior urethral valves was confirmed postnatally. Nonobstructive etiologies included the megacystis-megaureter association in 6 cases and the prune-belly syndrome in 1. Seven of the 8 patients with posterior urethral valves had moderate to severe oligohydramnios, whereas all but 1 with a nonobstructive etiology had normal amniotic fluid. Seven of the 8 cases with posterior urethral valves had a marked bilateral increase in renal echogenicity, while none of the nonobstructive cases had this finding.
Increased renal echogenicity and oligohydramnios in the setting of bladder distension are highly predictive (87%) of an obstructive etiology. This finding is important in the prenatal counseling and treatment of boys with bilateral hydronephrosis and marked bladder dilatation.
男性胎儿子宫内膀胱扩张合并双侧肾盂积水可能由多种病理过程引起。膀胱增大患者的产前和产后治疗取决于导致这些变化的具体病因。我们提出了用于区分这些胎儿梗阻性和非梗阻性病因的特定超声标准。
我们回顾了18例子宫内膀胱明显扩张病例的病历和产前影像学研究，这些病例在出生后确诊为后尿道瓣膜、巨膀胱-巨输尿管综合征或梅干腹综合征。在得知具体诊断之前评估羊水体积和肾脏回声。羊水过少分为轻度、中度或重度。肾脏回声增强定义为肾皮质和/或髓质的回声高于相邻肝脏组织。还回顾了产后影像学、临床过程和结局。
该研究包括15例有充分随访的病例，其中8例在出生后确诊为后尿道瓣膜。非梗阻性病因包括6例巨膀胱-巨输尿管综合征和1例梅干腹综合征。8例后尿道瓣膜患者中有7例有中度至重度羊水过少，而除1例非梗阻性病因患者外，其余患者羊水均正常。8例后尿道瓣膜病例中有7例肾脏回声明显双侧增强，而非梗阻性病例均无此表现。
膀胱扩张情况下肾脏回声增强和羊水过少对梗阻性病因具有高度预测性（87%）。这一发现对于双侧肾盂积水和膀胱明显扩张男孩的产前咨询和治疗具有重要意义。
