OBJECTIVE To assess the timing of patency and late failure (secondary azoospermia) after vasovasostomy (VV) using standardized kinetics definitions. DESIGN Retrospective cohort study. SETTING University-affiliated hospital. PATIENT(S) Patients with obstructive azoospermia. INTERVENTION(S) Vasovasostomy. MAIN OUTCOME MEASURE(S) Univariate and multivariate logistic regression assessed predictors of patency and late failure. Patency was defined as any sperm return to the ejaculate; and >2 million total motile sperm (TMS) in ejaculate. Late failure after VV was defined as azoospermia; or <2 million TMS in ejaculate. RESULT(S) 429 men underwent VV, with median follow up of 242 days. Mean time to patency was 3.25 months versus 5.29 months in the "any sperm" versus ">2 million TMS" groups. Finding sperm intraoperatively during VV significantly improved patency rates in multivariable analysis (odds ratio [OR] 4.22). This association was further boosted when sperm was found bilaterally (OR 6.70). Late failure rate (azoospermia) was 10.6% at mean time of 14.1 months and 23% for <2 million, at mean time of 15.7 months. When assessing predictors of late failure, intraoperative motile sperm bilaterally was a statistically significant protective factor on multivariate analysis (hazard ratio 0.22). CONCLUSION(S) Vasovasostomy remains highly efficacious in treating obstructive azoospermia. Young patients, shorter obstructive intervals, and sperm identified intraoperatively predict improved outcomes. Clinicians can expect VV patency in 3 months and late failure within the first 2 years after surgery. However, patency rates, late failure rates, and kinetics vary by definition.

中文翻译：

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血管造口术：通畅的动力学和预测因素

目的 使用标准化动力学定义评估输精管造口术 (VV) 后通畅和晚期失败（继发性无精子症）的时间。设计 回顾性队列研究。设置 大学附属医院。患者 (S) 阻塞性无精子症患者。干预（S）血管造口术。主要结果测量 单变量和多变量逻辑回归评估通畅和晚期失败的预测因素。通畅定义为任何精子返回射精；射精中的总活动精子 (TMS) 超过 200 万。VV 后晚期失败定义为无精子症；或 <200 万 TMS 射精。结果 429 名男性接受了 VV，中位随访时间为 242 天。“任何精子”组和“200 万 TMS”组的平均通畅时间分别为 3.25 个月和 5.29 个月。在 VV 术中发现精子在多变量分析中显着提高了通畅率（优势比 [OR] 4.22）。当双侧发现精子时，这种关联进一步增强（OR 6.70）。晚期失败率（无精子症）在 14.1 个月的平均时间为 10.6%，对于 <200 万，平均时间为 15.7 个月，为 23%。在评估晚期失败的预测因素时，术中双侧活动精子是多变量分析中具有统计学意义的保护因素（风险比 0.22）。结论(S) 输精管造口术在治疗梗阻性无精子症方面仍然非常有效。年轻患者、较短的阻塞间隔和术中发现的精子可预测改善的结果。临床医生可以预期 3 个月内 VV 通畅，并在手术后的前 2 年内出现晚期失败。然而，通畅率，