Experimental analysis of risk factors for aneurismal sac re-expansion after stent-grafting

【导言】根据支架置入术的临床应用，尽管动脉瘤已形成血栓，但仍有动脉瘤大小未缩小的病例。此外，这些病例通常伴有继发性破裂的高风险。本研究的目的是持续测量血液流动被支架植入阻断的动脉瘤中排除囊压力的变化，并阐明在手术后期成功减小动脉瘤大小和降低动脉瘤内排除囊压力的更多有用因素。【对象和方法】用猪连续测量血管支架置入后血流阻塞动脉瘤的排除囊压变化，并比较动脉瘤大小的变化。建立无内漏、ⅰ型和ⅱ型内漏的动脉瘤模型，以指示影响动脉瘤内压的因素。术后6个月，使用植入体内的遥测压力传感器连续测量动脉瘤内动脉血压和内压。此外，上述实验结果允许修复支架存在的问题，并将支架放置在无内漏和I型和II型内漏的动脉瘤模型中。此外，将猪处死，检查动脉瘤内血栓的性质，并对动脉瘤壁进行病理检查。【结果】体压和动脉瘤内压与支架移植部分的厚度及有无内漏有显著相关性。此外，无论着落区长度如何，当血管造影未发现内漏时，动脉瘤内压与全身血压相比显著下降。对于I型和II型内漏，动脉瘤内排除囊压与急性期全身血压相比显著下降。然而，在动脉瘤内腔长期存在的情况下，动脉瘤内压和全身血压没有显著差异，并且可以注意到红色血栓。【讨论与结论】目前还没有研究同时测量支架置入术后几个月的体血压和动脉瘤内压，并报道其与动脉瘤大小的关系，但本研究明确了动脉瘤大小与体血压和动脉瘤内压的关系。在急性期，内漏不会引起动脉瘤内压升高，但尽管血管造影没有明显改变的证据，动脉瘤内压升高仍被注意到。当内漏持续6个月或更长时间时，治疗应迅速转为手术。少

[Introduction] There are, in accordance with clinical use of stent graft placement, cases in which aneurysm size is not reduced despite the aneurysm being thrombosed. In addition, these cases are often reported to involve a high risk of secondary rupture. The aim of this study was to continuously measure excluded sac pressure changes in an aneurysm in which blood flow had been blocked by stent graft placement and to clarify more useful factors for successful reduction of aneurysm size and decrease of excluded sac pressure within the aneurysm in the late stages of this procedure.[Subjects and methods] Excluded sac pressure changes in an aneurysm in which blood flow was blocked after stent graft placement were continuously measured using pigs, and changes in aneurysm size were compared. An aneurysm model with no endoleaks and type I and type II endoleaks was created to indicate factors affecting internal pressure within the aneurysm. Arterial blood pressure and internal pressure within t … More he aneurysm were continuously measured simultaneously for 6 months postoperatively using a telemetric pressure sensor implanted in the body. In addition, the above experimental results allowed remediation of problems with the stent graft, and the graft was placed in an aneurysm model with no endoleaks and type I and type II endoleaks. In addition, the pigs were sacrificed, and the nature of the thrombus in the aneurysm was examined together with a pathological study of the aneurysmal wall. [Results] Systemic blood pressure and internal pressure within the aneurysm had a significant correlation to the thickness of the graft portion of the stent graft and the presence or absence of an endoleak. In addition, internal pressure within the aneurysm dropped significantly in comparison to systemic blood pressure when an endoleak was not found in angiography, regardless of the length of the landing zone. With both type I and type II endoleaks, excluded sac pressure within the aneurysm dropped significantly in comparison to systemic blood pressure in acute stages. In cases where an endoleak remained over the long-term, however, there was no significant difference in internal pressure within the aneurysm and systemic blood pressure, and a red thrombus was noted. [Discussion and Conclusion] No studies simultaneously measured systemic blood pressure and internal pressure within the aneurysm for several months after stent graft placement and reported on the relationship to aneurysm size, but this study clarified the relationship between aneurysm size and systemic blood pressure and internal pressure within the aneurysm. An endoleak did not cause internal pressure within the aneurysm to rise during acute stages, but a rise in internal pressure within the aneurysm was noted despite the lack of evidence of major changes in angiography. Treatment should be quickly converted to surgery when an endoleak continues for 6 months or longer. Less