Semen analysis charts of four men with presumed early recanalization. Sperm concentration is illustrated on a log scale. Since a logarithmic scale has no true zero, we used <100 on the graph to indicate azoospermia. The dotted line indicates low sperm cut-off (1,000,000 sperm/mL) according to reviewers' consensus (see Table 1). For case no 8, pre-vasectomy sperm concentrations were not available. We assumed a count of 20,000,000 sperm/mL with presence of motile sperm.