Docimo S G, Luetic T, Crone R K, Davies P, Reid L, Retik A B, Mandell J
Children's Hospital, Boston, Massachusetts.
J Urol. 1989 Aug;142(2 Pt 2):657-60; discussion 667-8. doi: 10.1016/s0022-5347(17)38845-6.
The lethal feature of male newborns with severe bladder outlet obstruction and oligohydramnios is pulmonary hypoplasia. We report a fetal lamb model of bladder outlet obstruction created in the early second trimester, and morphometric analysis of the profound pulmonary hypoplasia that resulted. At 55 to 65 days of gestation 8 consecutive male fetuses underwent surgical clipping of the urethra and urachus near the abdominal wall. A sham operation was performed in 1 female fetus. The lambs were delivered by cesarean section 10 weeks later. The right lungs were immediately fixed at a distending pressure of 25 cm. water. The results of the morphometric studies were compared to control animals from our earlier study of normal fetal lamb lung development; slides for both studies were scored in a blind, randomized fashion by 1 of us (S. G. D.). Although mean body weights for the groups were similar, mean right lung volume in the operated lambs was 63.8 cM.3 compared to 158 cM.3 in the control animals and 137 cM.3 in the sham operated fetus (p less than 0.0005). Relative volume of respiratory tissue was 87 per cent in the operated animals, and 92 per cent in the controls and the sham operated fetus (p less than 0.0005). Microscopic morphometry revealed an increased relative volume of inter-alveolar tissue in the experimental animals (35 compared to 23 per cent in the normal lambs, p less than 0.05), with a corresponding decrease in relative airspace volume. Alveolar numerical density and alveolar surface density were not statistically different between the groups, although total alveolar number and surface area were substantially decreased in the operated lambs due to the reduced mean lung volume. Mean alveolar wall thickness was increased at 3.6 microM. in the operated group versus 2.1 microM. in the normal group (p less than 0.0005) and 2.8 microM. in the sham operated fetus. Thus, the lung in the lamb with severe bladder outlet obstruction is hypoplastic and immature.
患有严重膀胱出口梗阻和羊水过少的男性新生儿的致命特征是肺发育不全。我们报告了一种在妊娠中期早期创建的胎儿羔羊膀胱出口梗阻模型，以及对由此导致的严重肺发育不全的形态计量学分析。在妊娠55至65天时，连续8只雄性胎儿在腹壁附近接受了尿道和脐尿管的手术夹闭。对1只雌性胎儿进行了假手术。10周后通过剖宫产分娩羔羊。立即将右肺在25厘米水柱的扩张压力下固定。将形态计量学研究结果与我们早期对正常胎儿羔羊肺发育研究中的对照动物进行比较；两项研究的切片均由我们中的一人（S.G.D.）以盲法、随机方式评分。尽管两组的平均体重相似，但手术羔羊的平均右肺体积为63.8立方厘米，而对照动物为158立方厘米，假手术胎儿为137立方厘米（p<0.0005）。手术动物的呼吸组织相对体积为87%，对照组和假手术胎儿为92%（p<0.0005）。微观形态计量学显示，实验动物的肺泡间组织相对体积增加（正常羔羊为23%，实验动物为35%，p<0.05），相应地气腔相对体积减少。两组之间的肺泡数量密度和肺泡表面密度无统计学差异，尽管由于平均肺体积减小，手术羔羊的总肺泡数和表面积大幅减少。手术组的平均肺泡壁厚度增加至3.6微米，正常组为2.1微米（p<0.0005），假手术胎儿为
