Ullery Brant W, Lee George K, Lee Jason T
Division of Vascular Surgery, Stanford University Medical Center, Stanford, Calif.
Division of Vascular Surgery, Stanford University Medical Center, Stanford, Calif.
J Vasc Surg. 2014 Oct;60(4):900-7. doi: 10.1016/j.jvs.2014.04.055. Epub 2014 May 24.
Shuttering occurs when a scallop or fenestration does not align perfectly with the target vessel ostium and is potentially minimized by stenting. The current United States Food and Drug Administration-approved fenestrated endovascular aneurysm repair (f-EVAR) device is most commonly configured with an unstented superior mesenteric artery (SMA) scallop, thereby subjecting the SMA to risk of partial coverage. We aimed to describe the incidence, severity, and clinical effect of SMA shuttering during f-EVAR.
Patients undergoing f-EVAR using the commercially available Zenith (Cook Medical, Bloomington, Ind) fenestrated stent graft system containing an SMA scallop at our institution between September 2012 and January 2014 were included for analysis. Corrected multiplanar reformatted images on postoperative computed tomographic angiography were reviewed to measure SMA shuttering, defined as the percentage of scallop misalignment relative to the SMA ostial diameter.
Of the 28 f-EVAR cases performed at our institution during the study period, 18 patients (78% male) had an SMA scallop and were included in this analysis. The median age was 78 years (interquartile range [IQR], 72-81 years), and the median abdominal aortic aneurysm size was 61 mm (IQR, 56-64 mm). Fifty-one vessels were targeted (18 SMA scallops, 32 renal fenestrations, 1 renal snorkel), with covered stents placed in all fenestrations. Target vessel catheterization and successful branch stent deployment was achieved in 100% of patients. SMA shuttering measured on postoperative computed tomographic angiography of any amount occurred in 50% of patients (range of SMA shuttering, 12%-40%). The severity of SMA shuttering varied: one patient had 11% to 20%, four had 21% to 30%, and four had 31 to 40%. When compared with patients without shuttering, patients with any SMA shuttering were noted to have a shorter infra-SMA neck length (17 vs. 25 mm; P = .007), higher volume of intraprocedural contrast administration (100 vs. 66 mL; P = .001), and had a trend toward longer procedural durations (240 vs. 188 minutes; P = .09). No association was found between SMA shuttering and the preoperative measured clock position of the visceral vessels, percentage of device oversizing, number of target vessels per patient, aortic diameter at the SMA or seal zone, aneurysm neck morphology, infrarenal neck length, scallop width, or SMA ostial diameter. No acute or chronic events of mesenteric ischemia were noted during a median clinical follow-up period of 11 months (IQR, 5-14 months).
Even with the custom design of currently available fenestrated technology, shuttering of the SMA occurred in one-half of the patients in our cohort, although no clinical events were noted. Further details of the incidence, magnitude, and tolerance of SMA shuttering during f-EVAR are warranted to fully understand the clinical implication of this radiographic finding. Future design considerations for advanced EVAR should take into account SMA shuttering to further refine operative planning.
当扇贝形或开窗与目标血管开口未完全对齐时会发生封堵，而通过支架置入可潜在地将其最小化。目前美国食品药品监督管理局批准的开窗式血管内动脉瘤修复术（f-EVAR）装置最常见的配置是无支架的肠系膜上动脉（SMA）扇贝形结构，从而使SMA有部分覆盖的风险。我们旨在描述f-EVAR期间SMA封堵的发生率、严重程度及临床影响。
纳入2012年9月至2014年1月在我们机构接受使用市售含SMA扇贝形结构的Zenith（库克医疗公司，印第安纳州布卢明顿）开窗式支架移植物系统进行f-EVAR的患者进行分析。回顾术后计算机断层血管造影的校正多平面重建图像以测量SMA封堵，定义为扇贝形与SMA开口直径的错位百分比。
在研究期间我们机构进行的28例f-EVAR病例中，18例患者（78%为男性）有SMA扇贝形结构并纳入本分析。中位年龄为78岁（四分位间距[IQR]，72 - 81岁），中位腹主动脉瘤大小为61 mm（IQR，56 - 64 mm）。共针对51条血管（18个SMA扇贝形结构、32个肾开窗、1个肾弯管），所有开窗均置入了覆膜支架。100%的患者实现了目标血管插管及成功的分支支架置入。术后计算机断层血管造影测量发现50%的患者出现了任何程度的SMA封堵（SMA封堵范围为12% - 40%）。SMA封堵的严重程度各不相同：1例患者为11%至20%，4例为21%至30%，4例为31%至40%。与无封堵的患者相比，有任何SMA封堵的患者SMA下方颈部长度较短（17 vs. 25 mm；P = 0.007），术中造影剂用量较大（100 vs. 66 mL；P = 0.001），且手术时间有延长趋势（240 vs. 188分钟；P = 0.09）。未发现SMA封堵与术前测量的内脏血管时钟位置（clock position）、装置过大百分比、每位患者的目标血管数量、SMA或密封区处的主动脉直径、动脉瘤颈部形态、肾下颈部长度、扇贝形宽度或SMA开口直径之间存在关联。在中位11个月（IQR，5 - 14个月）的临床随访期间未发现肠系膜缺血的急性或慢性事件。
即使采用目前可用的定制开窗技术设计，我们队列中有一半的患者发生了SMA封堵，尽管未观察到临床事件。有必要进一步详细了解f-EVAR期间SMA封堵的发生率、程度和耐受性，以充分理解这一影像学发现的临床意义。未来先进血管内动脉瘤修复术（EVAR）的设计考虑应顾及SMA封堵，以进一步完善手术规划。
