Steward Bonika, Hays Melissa, Sokal David
Family Health International, Research Triangle Park, North Carolina 27709, USA.
J Urol. 2008 Nov;180(5):2119-23. doi: 10.1016/j.juro.2008.07.062. Epub 2008 Sep 18.
Semen analysis is a common laboratory procedure but few data are available to support recommendations as to whether centrifugation is necessary in the post-vasectomy context. We evaluated the accuracy of a pre-centrifugation determination of azoospermia compared with post-centrifugation results.
We conducted a secondary analysis of data from 3,205 semen analyses performed during a randomized clinical trial of 2 vasectomy techniques--ligation and excision with fascial interposition vs ligation and excision without fascial interposition. We performed brief, initial microscopic examinations to categorize sperm numbers per high power field to decide whether centrifugation or dilution was needed before estimation of sperm concentration. For specimens initially categorized as azoospermic, we reviewed the post-centrifugation semen analysis results to estimate the accuracy of the initial finding.
Of 2,104 samples categorized as azoospermic before centrifugation, post-centrifugation analysis demonstrated that all but 4 (99.8%) were azoospermic or had a sperm concentration of less than 100,000 sperm per ml. Four samples from 1 study site had counts between 104,000 and 315,000 sperm per ml. Of 1,610 apparently azoospermic samples obtained at 10 weeks or later after vasectomy there were 12 (0.7%) that had some motile sperm identified after centrifugation but the numbers of motile sperm were low (mean 1,124 motile sperm per ml, range 238 to 3,710).
Microscopic examination of uncentrifuged specimens is a reliable method for identifying semen samples after vasectomy with more than 100,000 sperm per ml.
精液分析是一项常见的实验室检查，但关于在输精管结扎术后是否有必要进行离心处理，几乎没有数据支持相关建议。我们比较了离心前无精子症判定结果与离心后结果的准确性。
我们对一项随机临床试验中进行的3205次精液分析数据进行了二次分析，该试验比较了两种输精管结扎技术——筋膜间置结扎与切除术和无筋膜间置结扎与切除术。我们进行了简短的初始显微镜检查，以对每个高倍视野的精子数量进行分类，从而在估计精子浓度之前确定是否需要离心或稀释。对于最初分类为无精子症的标本，我们回顾了离心后的精液分析结果，以估计初始结果的准确性。
在离心前分类为无精子症的2104个样本中，离心后分析表明，除4个样本（99.8%）外，其余样本均为无精子症或精子浓度低于每毫升100,000个精子。来自1个研究地点的4个样本的精子计数在每毫升104,000至315,000个精子之间。在输精管结扎术后10周或更晚获得的1610个明显无精子症样本中，有12个（0.7%）在离心后发现有一些活动精子，但活动精子数量较少（平均每毫升1124个活动精子，范围为238至3710个）。
对未离心标本进行显微镜检查是一种可靠的方法，可用于识别输精管结扎术后每毫升精子超过100,000个的精液样本。
