Abstract：
OBJECTIVE: After endovascular aortic aneurysm repair (EVAR), the Society for Vascular Surgery recommends a computed tomography (CT) scan ≤30 days, followed by annual imaging. We sought to describe long-term adherence to surveillance guidelines among United States Medicare beneficiaries and determine patient and hospital factors associated with incomplete surveillance.
METHODS: We analyzed fee-for-service Medicare claims for patients receiving EVAR from 2002 to 2005 and collected all relevant postoperative imaging through 2011. Additional data included patient comorbidities and demographics, yearly hospital volume of abdominal aortic aneurysm repair, and Medicaid eligibility. Allowing a grace period of 3 months, complete surveillance was defined as at least one CT or ultrasound assessment every 15 months after EVAR. Incomplete surveillance was categorized as gaps for intervals >15 months between consecutive images as or lost to follow-up if >15 months elapsed after the last imaging.
RESULTS: Our cohort comprised 9695 patients. Median follow-up duration was 6.1 years. A CT scan ≤30 days of EVAR was performed in 3085 (31.8%) patients and ≤60 days in 60.8%. The median time to the postoperative CT was 38 days (interquartile range, 25-98 days). Complete surveillance was observed in 4169 patients (43.0%). For this group, the mean follow-up time was shorter than for those with incomplete surveillance (3.4 ± 2.74 vs 6.5 ± 2.1 years; P < .001). Among those with incomplete surveillance, follow-up became incomplete at 3.3 ± 1.9 years, with 57.6% lost to follow-up, 64.1% with gaps in follow-up (mean gap length, 760 ± 325 days), and 37.6% with both. A multivariable analysis showed incomplete surveillance was independently associated with Medicaid eligibility (hazard ratio [HR], 1.42; 95% confidence interval [CI], 1.29-1.55; P < .001), low-volume hospitals (HR, 1.12; 95% CI, 1.05-1.20; P < .001), and ruptured abdominal aortic aneurysm (HR, 1.51; 95% CI, 1.24-1.84; P < .001).
CONCLUSIONS: Postoperative imaging after EVAR is highly variable, and less than half of patients meet current surveillance guidelines. Additional studies are necessary to determine if variability in postoperative surveillance affects long-term outcomes.
METHODS: We analyzed fee-for-service Medicare claims for patients receiving EVAR from 2002 to 2005 and collected all relevant postoperative imaging through 2011. Additional data included patient comorbidities and demographics, yearly hospital volume of abdominal aortic aneurysm repair, and Medicaid eligibility. Allowing a grace period of 3 months, complete surveillance was defined as at least one CT or ultrasound assessment every 15 months after EVAR. Incomplete surveillance was categorized as gaps for intervals >15 months between consecutive images as or lost to follow-up if >15 months elapsed after the last imaging.
RESULTS: Our cohort comprised 9695 patients. Median follow-up duration was 6.1 years. A CT scan ≤30 days of EVAR was performed in 3085 (31.8%) patients and ≤60 days in 60.8%. The median time to the postoperative CT was 38 days (interquartile range, 25-98 days). Complete surveillance was observed in 4169 patients (43.0%). For this group, the mean follow-up time was shorter than for those with incomplete surveillance (3.4 ± 2.74 vs 6.5 ± 2.1 years; P < .001). Among those with incomplete surveillance, follow-up became incomplete at 3.3 ± 1.9 years, with 57.6% lost to follow-up, 64.1% with gaps in follow-up (mean gap length, 760 ± 325 days), and 37.6% with both. A multivariable analysis showed incomplete surveillance was independently associated with Medicaid eligibility (hazard ratio [HR], 1.42; 95% confidence interval [CI], 1.29-1.55; P < .001), low-volume hospitals (HR, 1.12; 95% CI, 1.05-1.20; P < .001), and ruptured abdominal aortic aneurysm (HR, 1.51; 95% CI, 1.24-1.84; P < .001).
CONCLUSIONS: Postoperative imaging after EVAR is highly variable, and less than half of patients meet current surveillance guidelines. Additional studies are necessary to determine if variability in postoperative surveillance affects long-term outcomes.
摘要：
目的：主动脉瘤腔内修复术（EVAR）后，血管外科学会推荐计算机断层扫描（CT）扫描≤30天，其次是年度成像。我们试图描述美国医疗保险受益人长期遵守监测指南的情况，并确定与不完全监测相关的患者和医院因素。
方法：我们分析了2002年至2005年接受EVAR的患者的按服务付费的Medicare索赔，并收集了到2011年所有相关的术后影像学检查。其他数据包括患者合并症和人口统计，每年的腹主动脉瘤修复术，和医疗补助资格。允许3个月的宽限期，完整监测定义为EVAR后每15个月至少进行一次CT或超声评估.不完全监测被归类为间隔>15个月的连续图像之间的间隙，如果在最后一次成像后超过15个月，则丢失随访。
结果：我们的队列包括9695名患者。中位随访时间为6.1年。在3085例（31.8％）患者中进行了≤30天的EVARCT扫描，在60.8％的患者中进行了≤60天的EVAR扫描。术后CT的中位时间为38天（四分位距，25-98天）。在4169例患者中观察到完全监测(43.0%)。对于这个群体来说,平均随访时间短于未完成监测的患者(3.4±2.74vs6.5±2.1年;P<.001)。在那些监测不完全的人中，随访在3.3±1.9年时变得不完整，57.6%的人失去了随访，64.1%在随访中有缺口(平均缺口长度，760±325天)，两者均为37.6%。多变量分析显示，不完全监测与医疗补助资格独立相关(风险比[HR]，1.42；95%置信区间[CI]，1.29-1.55;P<.001),低容量医院(HR，1.12；95%CI，1.05-1.20；P<.001），和破裂的腹主动脉瘤（HR，1.51；95%CI，1.24-1.84；P<.001）。
结论：EVAR术后影像学变化很大，不到一半的患者符合目前的监测指南。需要进一步的研究来确定术后监测的变异性是否会影响长期结果。
方法：我们分析了2002年至2005年接受EVAR的患者的按服务付费的Medicare索赔，并收集了到2011年所有相关的术后影像学检查。其他数据包括患者合并症和人口统计，每年的腹主动脉瘤修复术，和医疗补助资格。允许3个月的宽限期，完整监测定义为EVAR后每15个月至少进行一次CT或超声评估.不完全监测被归类为间隔>15个月的连续图像之间的间隙，如果在最后一次成像后超过15个月，则丢失随访。
结果：我们的队列包括9695名患者。中位随访时间为6.1年。在3085例（31.8％）患者中进行了≤30天的EVARCT扫描，在60.8％的患者中进行了≤60天的EVAR扫描。术后CT的中位时间为38天（四分位距，25-98天）。在4169例患者中观察到完全监测(43.0%)。对于这个群体来说,平均随访时间短于未完成监测的患者(3.4±2.74vs6.5±2.1年;P<.001)。在那些监测不完全的人中，随访在3.3±1.9年时变得不完整，57.6%的人失去了随访，64.1%在随访中有缺口(平均缺口长度，760±325天)，两者均为37.6%。多变量分析显示，不完全监测与医疗补助资格独立相关(风险比[HR]，1.42；95%置信区间[CI]，1.29-1.55;P<.001),低容量医院(HR，1.12；95%CI，1.05-1.20；P<.001），和破裂的腹主动脉瘤（HR，1.51；95%CI，1.24-1.84；P<.001）。
结论：EVAR术后影像学变化很大，不到一半的患者符合目前的监测指南。需要进一步的研究来确定术后监测的变异性是否会影响长期结果。
