Grogan Jennifer, Castilla Maria, Lozanski Laurie, Griffin Andrea, Loth Frank, Bassiouny Hisham
Department of Surgery, Vascular Section, University of Chicago, IL 60637, USA.
J Vasc Surg. 2005 Jun;41(6):1000-6. doi: 10.1016/j.jvs.2005.02.019.
Increasing use of primary arteriovenous fistulae (pAVFs) is a desired goal in hemodialysis patients (National Kidney Foundation /Dialysis Outcome Quality Initiative guidelines). However, in many instances, pAVFs fail to adequately mature due to ill-defined mechanisms. We therefore investigated pAVFs with color duplex ultrasound (CDU) surveillance 4 to 12 weeks postoperatively to identify hemodynamically significant abnormalities that may contribute to pAVF failure.
From March 2001 to October 2003, 54 upper extremity pAVFs were subjected to CDU assessment before access. A peak systolic velocity ratio (SVR) of >/=2:1 was used to detect >/=50% stenosis involving arterial inflow and venous outflow, whereas an SVR of >/=3:1 was used to detect >/=50% anastomotic stenosis. CDU findings were compared with preoperative vein mapping and postoperative fistulography when available.
Of 54 pAVFs, there were 23 brachiocephalic, 14 radiocephalic, and 17 basilic vein transpositions. By CDU surveillance, 11 (20%) were occluded and 14 (26%) were negative. Twenty-nine (54%) pAVFs had 38 hemodynamically significant CDU abnormalities. These included 16 (42%) venous outflow, 13 (34%) anastomotic, and 2 (5%) inflow stenoses. In seven (18%), branch steal with reduced flow was found. In 35 of 54 (65%) pAVFs, preoperative vein mapping was available and demonstrated adequate vein size (>/=3 mm) and outflow in 86% of cases. Twenty-one fistulograms (38%) were available for verifying the CDU abnormalities. In each fistulogram, the arterial inflow, anastomosis, and venous outflow were compared with the CDU findings (63 segments). The sensitivity, specificity, and accuracy of CDU in detecting pAVF stenoses >/=50% were 93%, 94%, was 97%, respectively.
Before initiation of hemodialysis, an unexpectedly high prevalence of critical stenoses was found in patent pAVFs using CDU surveillance. These de novo stenoses appear to develop rapidly after arterialization of the upper extremity superficial veins and can be reliably detected by CDU surveillance. Turbulent flow conditions in pAVFs may play a role in inducing progressive vein wall and valve leaflet intimal thickening, although stenoses may be due to venous abnormalities that predate AVF placement. Routine CDU surveillance of pAVFs should be considered to identify and correct flow-limiting stenoses that may compromise pAVF long-term patency and use.
增加自体动静脉内瘘（pAVF）的使用是血液透析患者的一个理想目标（美国国家肾脏基金会/透析预后质量倡议指南）。然而，在许多情况下，由于机制不明，pAVF未能充分成熟。因此，我们在术后4至12周用彩色多普勒超声（CDU）监测pAVF，以识别可能导致pAVF失败的血流动力学显著异常。
2001年3月至2003年10月，54例上肢pAVF在使用前接受了CDU评估。收缩期峰值流速比（SVR）≥2:1用于检测动脉流入和静脉流出中≥50%的狭窄，而SVR≥3:1用于检测≥50%的吻合口狭窄。如有术前静脉造影和术后瘘管造影，将CDU检查结果与之进行比较。
54例pAVF中，有23例为头臂型，14例为桡动脉-头静脉型，17例为贵要静脉转位型。通过CDU监测，11例（20%）闭塞，14例（26%）无异常。29例（54%）pAVF有38处血流动力学显著的CDU异常。其中包括16处（42%）静脉流出道狭窄、13处（34%）吻合口狭窄和2处（5%）流入道狭窄。7例（18%）发现有窃血伴血流减少。54例pAVF中的35例（65%）有术前静脉造影，其中86%的病例显示静脉大小合适（≥3mm）且有流出道。21例瘘管造影（38%）可用于验证CDU异常。在每例瘘管造影中，将动脉流入、吻合口和静脉流出与CDU检查结果（63个节段）进行比较。CDU检测≥50%的pAVF狭窄的敏感性、特异性和准确性分别为93%、94%和97%。
在开始血液透析前，使用CDU监测发现，在通畅的pAVF中，严重狭窄的发生率出乎意料地高。这些新生狭窄似乎在上肢浅静脉动脉化后迅速发展，并且可以通过CDU监测可靠地检测到。pAVF中的湍流情况可能在诱导静脉壁和瓣膜小叶内膜逐渐增厚中起作用，尽管狭窄可能是由于在AVF放置前就存在的静脉异常。应考虑对pAVF进行常规CDU监测，以识别和纠正可能损害pAVF长期通畅性和可用性的限流狭窄。
