Data: outcome of embolization of an endoleak type 2 after placement of an endoprosthesis for an infrarenal aorta aneurysm

<b>Objective:</b>The aim is to investigate the effect of transarterial (TA) and translumbar (TL) embolization of a type 2 endoleak (T2EL) after endovascular aneurysm repair (EVAR) of an infrarenal abdominal aortic aneurysm (AAA) on the evolution and rupture of the aneurysmal sac.<b>Methods:</b>A retrospective study was conducted including patients who underwent TA or TL embolization for a growing T2EL after EVAR from April 2001 to August 2022<b>. </b>Demographic data, used endograft, radiological data of the AAA and T2EL, embolization agents, techniques (TA or TL approach) and angiographical outcomes were collected from 48 patients with a total of 58 embolizations. The primary clinical outcome was rupture of the AAA. Secondary outcomes included T2EL recurrence, re-embolization of T2EL, aneurysm sac growth (≥5 mm), and mortality. Clinical success was defined as the absence of a 5 mm or greater increase in the aneurysm sac diameter<b>Results:</b>After primary T2EL embolizations, an increase in aneurysm sac was seen in 56.5% (n=26), stability in 30.4% (n=14) and regression in 13.0% (n=6). Recurrence of T2EL had a significant impact on clinical success. No difference in sac size after the TA and TL embolization was noted. Rupture was found in 4 patients, but in only one patent it was caused by an isolated T2EL. The effect of increase in aneurysm sac size on overall survival was not statistically significant. Additionally, no associations were observed between the outcome and clinical factors including gender, obesity, COPD, diabetes, hypertension, hypercholesterolemia, smoking, technique, used embolic agents and time from endoleak (EL) onset to embolization.<b>Conclusion:</b>With a very low number of subsequent AAA ruptures, few complications and a clinical success rate of 43.5%, embolization of a T2EL can be considered as a safe and relatively effective procedure.<b>Clinical impact:</b>Although the impact of a T2EL on the outcome of an endovascular repaired abdominal aortic aneurysm is not yet clarified, in daily practice, the endovascular embolization is a safe and effective option. Elimination or reduction of the volume of the endoleak can be obtained, and can probably prevent aortic rupture, which is reassuring for the treating physician and the patient. The embolization of the T2EL reduces the need for extra imaging or hospitalizations, lowers the risk of bleeding complications and minimizes healthcare costs. Moreover, this research found no outcome differences in the embolization techniques. This study contributes to the knowledge and treatment of T2EL, supporting clinicians in making better informed decisions, ultimately optimizing patient care.

**研究目标：** 本研究旨在探讨经动脉（transarterial, TA）与经腰入路（translumbar, TL）栓塞治疗肾下型腹主动脉瘤（infrarenal abdominal aortic aneurysm, AAA）血管腔内修复术（endovascular aneurysm repair, EVAR）后并发的2型内漏（type 2 endoleak, T2EL）对动脉瘤囊演化及破裂的影响。
**研究方法：** 本研究为回顾性研究，纳入2001年4月至2022年8月期间，因EVAR术后出现进行性增大的T2EL而接受TA或TL栓塞治疗的患者。研究收集了48例患者共58次栓塞操作的人口统计学资料、所用覆膜支架（endograft）、AAA及T2EL的影像学数据、栓塞剂、栓塞技术（TA或TL入路）以及血管造影结局。主要临床结局为AAA破裂；次要结局包括T2EL复发、T2EL再次栓塞、动脉瘤囊增大（≥5mm）以及全因死亡率。临床成功定义为动脉瘤囊直径未出现≥5mm的增加。
**研究结果：** 首次T2EL栓塞术后，56.5%（n=26）的患者出现动脉瘤囊增大，30.4%（n=14）的患者动脉瘤囊保持稳定，13.0%（n=6）的患者动脉瘤囊出现缩小。T2EL复发对临床成功具有显著影响。TA与TL栓塞术后的动脉瘤囊大小无显著差异。共4例患者发生AAA破裂，其中仅1例患者的破裂由孤立性T2EL所致。动脉瘤囊增大对总生存率的影响无统计学意义。此外，未观察到结局与各临床因素间存在关联，这些因素包括性别、肥胖、慢性阻塞性肺疾病（chronic obstructive pulmonary disease, COPD）、糖尿病、高血压、高胆固醇血症、吸烟史、栓塞技术、所用栓塞剂以及内漏（endoleak, EL）发病至栓塞的时间间隔。
**研究结论：** 本研究中后续AAA破裂发生率极低，并发症较少，临床成功率达43.5%，因此T2EL栓塞治疗可被视为一种安全且相对有效的诊疗手段。
**临床意义：** 尽管目前T2EL对EVAR术后腹主动脉瘤预后的影响尚未明确，但在日常临床实践中，血管腔内栓塞治疗是一种安全有效的可选方案。通过该治疗可实现内漏体积的消除或缩小，或可预防主动脉破裂，这对临床医师与患者而言均是令人安心的结果。T2EL栓塞治疗可减少额外影像学检查与住院需求，降低出血并发症风险，并降低医疗成本。此外，本研究未发现不同栓塞技术间的结局存在差异。本研究丰富了T2EL的诊疗相关知识，可辅助临床医师做出更充分的知情决策，最终优化患者照护质量。