移植血管动静脉内瘘(arteriovenous graft,AVG)指用一人工材料制成的血管桥接于动、静脉之间形成的内瘘，是血液透析血管通路的重要形式之一。血管狭窄是AVG最常见的并发症。
RENOVA，关键研究（Pivotal study）[1]：是透析通道移植血管动静脉内瘘再狭窄时，血管内覆膜支撑架和PTA治疗的随机对照多中心研究，截至发稿为止已经有了中期结果。
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美国13个医学中心参与了这项190例随机研究病人的研究。
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PTA+ePTFE 覆膜支撑架 vs 单独的PTA ：AVG 静脉吻合口狭窄（不限于PTA失败、移植血管完全阻塞除外）
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主要研究终点 - 治疗部位的初始开放率 (Treatment Area Primary Patency，TAPP)
- (Access Circuit Primary Patency，ACPP)
这项Pivotal研究的背景是：
1. 美国医疗保险（Medicare）终末期肾病（ ESRD）的年花费（美元）
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全部的终末期肾病 |
每个透析病人 |
透析通路良好的花费/每病人/年 |
透析通路失败花费/每病人/年 |
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1998 |
100亿 |
52000 |
11390 |
59000 |
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2004 |
180亿 |
65800 |
16500 |
75800 |
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2008 |
248亿 |
80600 |
22300 |
96300 |
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2010 |
283亿 |
86300 |
24600 |
107300 |
2. 移植血管内血栓形成的发生率仍然是需要更好处理的问题
血管介入干预事件发生率（2008）
|
年龄 |
AVF% |
AVG% |
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20-29 |
3.2 |
38.5 |
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30-39 |
4.3 |
17.9 |
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40-49 |
5.4 |
17.9 |
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50-59 |
3.1 |
17.9 |
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60-64 |
5.5 |
19.8 |
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65-69 |
4.4 |
15.6 |
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70-79 |
5.1 |
16.0 |
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80-84 |
7.2 |
10.2 |
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85+ |
4.0 |
21.2 |
U S Renal Data System, USRDS 2012 Annual Data Report: Atlas of Chronic Kidney Disease and End-Stage Renal Disease in the United States, National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, 2012.
支撑架分喇叭形和直形两种
- 喇叭形：在关键研究中的84%病人应用此型覆膜支撑架
- 喇叭口比体部直径大4mm
- 较大静脉与覆膜支撑架不匹配是可以使其直径相一致
Diagram of Flared v Straight Configurations
关键研究的6月结果：
Pivotal Study: 6-Month Results
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喇叭口覆膜支撑架* |
球囊扩张 |
P |
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TAPP（治疗部位的初始开放率） |
50.6% |
23.3% |
<0.001 |
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ACPP |
38.0% |
19.8% |
0.008 |
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Minimum Lumen Diameter (Treatment Area) |
5.1±1.5 mm |
3.3±1.5 mm |
<0.001 |
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% Stenosis (mean ± SD) |
32.1±19.8% |
59.2±19.6% |
<0.001 |
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Binary Restenosis (> 50%) |
28% |
78% |
<0.001 |
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Freedom From Subsequent Intervention |
32% |
16% |
0.03 |
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* FDA approved in 2008 for: Treatment of stenosis at the venous anastomosis of ePTFE or other synthetic arteriovenous (AV) access grafts
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关键研究的总结
Pivotal Trial: Summary
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Treatment Area Primary Patency (TAPP) |
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Access Circuit Primary Patency (ACPP) |
Improved 6 month TAPP & ACPP when stent graft used for treatment of venous anastomotic stenosis in patient, PTFE grafts
关键研究（Pivotal）的结论：
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肾透析动静脉瘘通道静脉吻合狭窄时，覆膜支撑架治疗优于球囊扩张术
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虽然对于合适的病人，AVGs表明可以考虑为长期方法，但超过6个月就能达到可接受的长期开放吗？还可以改善吗？
A Prospective, Randomized, Concurrently-Controlled Post-Approval Study of the FLAIR ENdOVAscular Stent Graft: RENOVA
RENOVA Clinical trial：（葡萄牙家用纸类设计制造的头牌大厂）
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2009.1
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目标：评价PTA+覆膜支撑架 vs PTA 长期安全性和有效性
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270 随机病例，28个研究单位
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主要目标：- ACPP；-IPF（Index of Patency Function）
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没有规定影像学随访研究
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24个月随访（以下为12个月的中期随访）
RENOVA的研究终点：
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Access Circuit Primary Patency (ACPP) - The interval following the index procedure until the next access thrombosis or reintervention
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Index of Patency Function (IPF) - time from index procedure to complete graft abandonment / # of re-interventions performed on AV access circuit to maintain access
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Safety - number of device and/or procedure related adverse events
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Secondarily, study of patency of treatment area (TAPP)
Stent Graft at the Venous Anastomosis
Patient Disposition at 12 Months
手术成功率
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手术成功率
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PTA
n=132
n (%) |
Stent Graft
n=138
n (%) |
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Anatomic Success: <30% residual stenosis |
99 ( 75.0)) |
112 ( 81.2) |
Hemodynamic Success:
Resolution of pre-procedure indicator of dysfunctionage |
130 ( 98.5) |
138 (100.0) |
Clinical Success:
At least one successful HD session post-procedure |
130 ( 98.5) |
135 ( 97.8) |
Procedure Success:
= Anatomic Success AND Hemodynamic or Clinical Successage |
99 ( 75.0) |
112 ( 81.2) |
12-Month ACPP
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ACPP=Access Circuit Primary Patency |
Pivotal vs RENOVA ACPP
12-Month IPF (QOL Surrogate)
12-Month Reinterventions
12-Month TAPP
Pivotal vs RENOVA TAPP
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12-Month Survival Curves
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Treatment Area Primary Patency (TAPP) |
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Access Circuit Primary Patency (ACPP) |
Sustained improvement at 12 months in TAPP & ACPP when stent graft used for treatment of venous anastomotic stenosis in patent, PTFE grafts
RENOVA 结论：
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12个月 RENOVA 中期结果-“工作”经验和评估
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与PTA 比较 PTA + 覆膜支撑架可以持续改善 ACPP；- 12个月时＞2.3倍（RENOVA）；6个月时＞1.9倍（Pivotal）。
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血栓和感染率两组无显著性差异
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覆膜支撑架应用是目前仅有的技术证实在6和12个月显著的开放优势好于球囊血管成形术
1. Haskal ZJ, Trerotola SO, Dolmatch B, et al. Stent graft versus balloon angioplasty for failing dialysis-access grafts. NEJM 2010; 362: 494-503
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