【Part.02】桡动脉闭塞（RAO）知多少？（双语）

In this study, although the incidence of severeflow reduction was low without any ischemic sequel, the incidence of RAO was not reported. We found that compression time of 15 minutes reduces RAO incidences significantly. Although the results were very promising and statistically significant, both of these studies were underpowered, with <200 patients in total in both arms .

在本研究中，虽然严重血流减少的发生率较低，无缺血性后遗症，但RAO的发生率未见报道。我们发现压缩时间为15分钟可显著降低RAO发生率。尽管结果非常有希望并且在统计上具有显著意义，但这两项研究的研究效力不足，两组总共有200名患者。

Furthermore, Politi et al reported increased bleeding in patients subjected to shorter compression time in patent hemostasis settings. More recently, duration of compression (>4 hours versus <4 hours) was studied in a large randomized study by Dharma et al. They found that duration of compression alone was a strong predictor of RAO (odds ratio 3.11; 95% CI 1.62–5.82), supporting the hypothesis of minimizing radial injury by reducing compression time Use of low molecular weight heparin (LMWH) is another routine practice to prevent thrombus formation and occlusive injury to the vessel by the mechanism as discussed above.

此外，Politi等人报道，在止血装置中压缩时间较短的患者出血增加。最近，Dharma等人在一项大型随机研究中研究了压缩持续时间(>4小时vs <4 小时)。他们发现压迫时间本身就是RAO的一个强有力的预测因子(优势比3.11;95% CI 1.62-5.82)，通过减少压迫时间来减少桡动脉损伤的假设，使用低分子肝素(LMWH)是另一种常规做法，通过上述机制防止血栓形成和血管闭塞性损伤。

In very early studies investigating the role of anticoagulants, Lefevre et al showed that the administration of heparin into the radial artery significantly reduced RAO. Our results show that incidence of RAO increases by reducing the dose of intra arterial heparin . We found that a heparin dose of 5000 IU was very effective in preserving the patency of radial artery when compared with lower doses of 2000 to 3000 IU (risk ratio 0.36 95% CI 0.17–0.76). No increased risk of bleeding was reported in the higher heparin arm.

在早期调查抗凝剂作用的研究中，Lefevre等人表明肝素进入桡动脉显著降低了RAO。我们的结果表明，减少动脉内肝素的剂量会增加RAO的发生率。我们发现，与较低剂量的2000 - 3000 IU相比，5000 IU的肝素剂量在保持桡动脉通畅方面非常有效(风险比0.36 95% CI 0.17-0.76)。肝素含量高的组出血风险未见增加。

We also observed a lower rate of RAO in the PCI setting (4.5%) compared to the diagnostic coronary angiogram setting (8.8%), which may relate to routine use of dual antiplatelet therapy and anticoagulants such as heparin or bivalirudin during the PCI procedure.

我们还观察到，与冠脉造影诊断组(8.8%)相比，PCI组的RAO率(4.5%)较低，这可能与PCI过程中常规使用双抗血小板治疗和抗凝剂(如肝素或比伐芦丁)有关。

Other anticoagulants such bivalirudin and warfarin have also been studied as potential alternatives but did not show any significant benefit over LMWH; therefore, LMWH remains a preferred anticoagulant due to lower costs. Our finding resonates with the recommendation made by the Society for Cardiovascular Angiography and Interventions transradial working group, which advocates the use of 5000 IU heparin in all patients undergoing TRA.

其他抗凝剂，如比伐芦丁和华法林也作为潜在的替代品进行了研究，但没有显示出比低分子肝素有任何显著的益处;因此，低分子肝素由于成本较低，仍然是首选的抗凝剂。我们的发现与心血管血管造影和经桡动脉介入协会工作组的建议一致，该工作组主张在所有接受TRA的患者中使用5000IU肝素。

Since the inception of TRA, there have been numerous advances in catheter and sheath designs to facilitate the procedure and minimize the insult to the artery. We studied radial sheath length and coating and found no inflfluence on RAO outcome. In a randomized trial of 790 compared long (23 cm) versus short (13 cm) sheaths and hydrophilic-coated or uncoated introducer sheaths, the authors found that neither sheath length nor coating affects RAO.

自TRA开展以来，导管和鞘的设计已经取得了许多进步，以促进手术过程并最大限度地减少对动脉的损伤。我们研究了桡动脉鞘的长度和涂层，发现对RAO结果无影响。在一项790个随机试验中，作者比较了长(23厘米)套和短(13厘米)鞘以及亲水性涂层或非涂层的引入套，发现护套长度和涂层都不会影响RAO。

However, it has been suggested that using a small-diameter guide catheter may reduce the injury to radial artery and result in fewer occlusion rates.52 This led to various innovations in the catheter design to minimize the outer diameter, including the development of sheathless guide catheters. Typically a 6-Fr sheathless guide catheter has an outer diameter that is smaller than that of a 5- Fr introducer sheath.

然而，有研究表明，使用小直径导管可减少对桡动脉的损伤，从而降低闭塞率这导致了导管设计的各种创新，以最小化外径，包括无鞘导管的发展。通常，6-Fr无鞘导管的外径比5- Fr导管的外径小。

We performed a pooled analysis to study the effect of various sizes (3, 4, 5, 6, 7, and 8 Fr) on incidence of RAO. We observed that RAO rates increase with increasing size of guide catheter systems used. Although the size of the catheter seems to correlate with incidence of RAO in these studies, the overall results failed to show a statistically significant benefit between smaller and larger catheter sizes. This may be because of under-representation of the smaller-size catheter in these studies.

我们进行了汇总分析，以研究不同大小(3、4、5、6、7和8 Fr)对RAO发生率的影响。我们观察到RAO率随着所使用导管系统尺寸的增加而增加。虽然在这些研究中，导管的尺寸似乎与RAO的发生率相关，但总体结果未能显示出更小和更大导管尺寸之间有统计学意义上的好处。这可能是因为这些研究中较小尺寸导管的代表性不足。

Further more, a fair number of studies were single cohort studies undertaken without true randomization and may be subject to selection biases.

In addition, there was no information available on the size (diameter) of radial artery in these studies, which may also explain the inconsistencies of relation of RAO to catheter size. Radial artery diameter and sheath-to-artery size ratio have been associated with better RAO outcomes. Nevertheless, the individual studies have shown promising results in reducing radial injury, supporting the hypothesis that small catheter size causes less radial artery trauma.

此外，在这些研究中没有关于桡动脉大小(直径)的信息，这也可能解释了RAO与导管尺寸关系的不一致。桡动脉直径和鞘-动脉尺寸比与更好的RAO结果相关。尽管如此，个别研究显示了减少桡动脉损伤的良好结果，支持导管尺寸小导致桡动脉损伤较小的假设。

Larger randomized studies with preprocedure ultrasonic assessment of radial artery diameter and sheath-to-artery ratio are required to show direct influence of catheter size on RAO. Patient’s baseline characteristics and procedural variables have been an area of interest to the researchers to predict occurrence of RAO (Table 4). Age, sex, and body mass index have been investigated to predict RAO at the patient level while sheath-to-artery diameter, duration of compression, and anticoagulation have been studied as possible predictors of RAO.

此外，在这些研究中没有关于桡动脉大小(直径)的信息，这也可能解释了RAO与导管尺寸关系的不一致。桡动脉直径和鞘-动脉尺寸比与更好的RAO结果相关。21,85尽管如此，个别研究显示了减少桡动脉损伤的良好结果，支持导管尺寸小导致桡动脉损伤较小的假设。

In our analysis, no factors were found to have consistent predictability of RAO among all the studies; however, age, sex, and body weight were most commonly reported predictors of RAO but there was no consistent direction of effect. For instance, 9 studies evaluated sex and 6 found that it was signifificant in predicting the RAO outcomes. Similarly, age was found to be a positive predictor in 3 of the 5 studies reporting on RAO. A more streamlined reporting of these variables in future trials may help in understanding the inflfluences on RAO.

在我们的分析中，在所有研究中，没有发现任何因素对RAO具有一致的可预测性;然而，年龄、性别和体重是RAO最常见的预测因素，但没有一致的影响方向。例如，9项研究评估了性别，6项研究发现它在预测RAO结果方面具有显著性。同样，在5项报告RAO的研究中，有3项发现年龄是一个积极的预测因素。在未来的试验中更精简地报告这些变量可能有助于理解对RAO的影响。

We also analyzed the effect of various pharmacological(药物) interventions in reducing RAO. In one study, administration of vasodilator cocktail in addition of to IV heparin before and after the procedure seems to have reduced the incidence of RAO. Ahmed et al also compared warfarin with LMWH to reduce RAO and concluded that warfarin was inferior to LMWH. In another prospective study, Zankl and colleagues studied the effificacy of LMWH in treating the RAO postprocedure and found that LMWH signifificantly improved the recanalization rates of radial artery.

我们还分析了各种药物干预在降低RAO中的作用。在一项研究中，除了静脉肝素外，在手术前后使用血管扩张剂鸡尾酒似乎降低了RAO的发生率。Ahmed等人也比较了华法林与低分子肝素降低RAO的效果，得出华法林不如低分子肝素的结论。在另一项前瞻性研究中，Zankl及其同事研究了低分子肝素治疗术后RAO的有效性，发现低分子肝素显著提高了桡动脉再通率。

These studies suggest that use of additional anticoagulation postprocedure may improve RAO outcome, but these studies were conducted without true randomization. Larger randomized studies are required to study the true effect of these medications in reducing RAO. Finally, Bernat et al30 used a nonpharmacological novel intervention of compressing the ulnar artery postprocedure to increase the flflow in radial artery once occluded. They found significantly lower rates of RAO post–ulnar artery compression and concluded that by doing so, flow through the radial artery increases, helping to reopen the artery postocclusion.

这些研究表明，术后使用额外的抗凝治疗可能改善RAO的结局，但这些研究没有真正的随机化。需要更大规模的随机研究来研究这些药物在降低RAO方面的真实效果。最后，Bernat等使用了一种非药物的新型干预措施，即术后压迫尺动脉以增加一旦闭塞的桡动脉的流量。他们发现RAO尺动脉后压迫率显著降低，并得出结论，通过这样做，桡动脉的流量增加，有助于重新打开动脉。

Our study has several limitations. Many of the studies were included were single-arm studies for which we were only able to evaluate the incidence of RAO. We included conference abstracts to reduce publication bias, but quality assessment from these studies was poor because reporting of methods was brief. While we found sufficient studies with similar interventions for statistical pooling, many of the included studies were underpowered.

我们的研究有几个局限性。许多纳入的研究都是单臂研究，我们只能评估RAO的发生率。我们纳入了会议摘要以减少发表偏倚，但这些研究的质量评估很差，因为方法的报告很简短。虽然我们发现有足够多的研究采用类似的干预措施进行统计汇总，但许多纳入的研究力度不足。