Background and aim

First pass effect (FPE) is defined as achieving a complete recanalization with a single thrombectomy device pass. Although clinically desired, FPE is reached in less than 30% of thrombectomy procedures. Multiple device passes are often necessary to achieve successful or complete recanalization. We performed a systematic review and meta-analysis to determine the recanalization rate after each pass of mechanical thrombectomy and its association with good neurological outcome.

Methods

A literature search was performed for studies reporting the number of device passes required for either successful (mTICI 2b or higher) or complete (mTICI 2c or higher) recanalization. Using random-effect meta-analysis, we evaluated the likelihood of recanalization and good neurological outcome (measured with the modified Rankin Score <2 at 90 days) after each device pass.

Results

Thirteen studies comprising 4197 patients were included. Among cases with failed first pass, 24% of them achieved final complete recanalization and 45% of them achieved final successful recanalization. Independently to the total number of previously failed attempts, the likelihood of achieving successful recanalization was 30% per pass, and the likelihood to achieve complete recanalization was about 20% per pass. The likelihood of good neurological outcome in patients with final successful recanalization decreased after each device pass: 55% after the first pass, 48% after the second pass, 42% after the third pass, 36% after the fourth pass, and 26% for 5 passes or more.

Conclusion

Each pass is associated with a stable likelihood of recanalization but a decreased likelihood of good neurological outcome.

中文翻译：

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中风血栓切除术中再通和良好神经学结果的单次分析：系统评价和荟萃分析

 背景和目的

首过效应（FPE）被定义为通过单次血栓切除装置实现完全再通。尽管临床上希望达到 FPE，但只有不到 30% 的血栓切除术能够达到 FPE。为了实现成功或完全的再通，通常需要多次通过装置。我们进行了系统回顾和荟萃分析，以确定每次机械血栓切除术后的再通率及其与良好神经学结果的关系。

 方法

对报告成功（mTICI 2b 或更高）或完全（mTICI 2c 或更高）再通所需的器械通过次数的研究进行了文献检索。使用随机效应荟萃分析，我们评估了每次装置通过后再通的可能性和良好的神经学结果（在 90 天时使用修改后的 Rankin 评分 <2 进行测量）。

 结果

纳入了 13 项研究，涉及 4197 名患者。在第一次失败的病例中，24%的患者实现了最终的完全再通，45%的患者实现了最终的成功再通。与之前失败的尝试总数无关，每次通过成功再通的可能性为 30%，每次通过实现完全再通的可能性约为 20%。每次装置通过后，最终成功再通的患者获得良好神经学结果的可能性降低：第一次通过后为 55%，第二次通过后为 48%，第三次通过后为 42%，第四次通过后为 36%，第二次通过后为 26% 5 次或以上。

 结论

每次通过都与再通的稳定可能性相关，但良好神经学结果的可能性降低。