来到利比里亚，我发现当地黑人脐疝发病率非常高。而且不仅是脐疝，还有腹股沟斜疝、上腹疝（epigastric hernia，国内也叫腹直肌分离）发病率也相当高。我查询了一下文献，发现黑人的脐疝发病率是白人的8倍。

     The incidence of umbilical hernia has been observed to be higher in black children. In a large comparative study, Evans reported an incidence of 24.7% among black infants and 3% among white infants（Principles and Practice of Pediatric Surgery 4^th Ed）。黑人婴儿脐疝发病率为24.7%，而白人婴儿只有3%。

    关于脐疝的手术指证：大部分脐疝患儿不需要手术。随着年龄增长，大部分脐疝可以自愈。嵌顿性和绞窄性疝是绝对手术指证。在我国小儿脐疝很少需要做手术。而利比里亚儿童脐疝不仅发病率高，而且需要做手术的患儿也多。急诊上经常能遇到绞窄性脐疝需要做手术的患儿。

    脐疝的手术年龄：5岁。Based on a review of the available data on closure rates, umbilical hernias that persist at 5 years of age should be repaired（Principles and Practice of Pediatric Surgery 4^th Ed）.脐疝嵌顿的整体发病率毕竟还是很低，因此5岁前只要不发生嵌顿是不需要做手术的。

    另外，疝环的大小和预后有很大关系。

    Walker performed a 6-year follow-up study of 314 black infants younger than 3 months. He observed that 96% of initial fascial defects of less than 0.5 cm closed spontaneously, but no defects greater than 1.5 cm closed during the 6-year observation period（Principles and Practice of Pediatric Surgery 4^th Ed）.96%的疝环小于0.5cm的脐疝能够自愈，但是疝环大于1.5cm的脐疝基本不能自行愈合，需要手术。