Robison J G, Elliott B M
Section of Vascular Surgery, Medical University of South Carolina, Charleston 29425.
Ann Vasc Surg. 1991 Mar;5(2):182-5. doi: 10.1007/BF02016753.
Duplex scanning used to determine graft flow velocities is an effective means of identifying lower extremity bypass grafts at risk for failure before they occlude. We implemented a graft surveillance protocol using duplex scanning and over a two-year interval evaluated fifty-four lower extremity bypasses utilizing graft flow velocities, ankle/brachial indices, and toe pressure measurements. Three patients were identified with grafts at risk for thrombosis. Of these patients, one had no evidence of arteriographic stenosis, one patient had clinical symptoms of reduced flow velocity measurements, and one's graft subsequently occluded during follow-up. Eight patients with graft flow velocities of greater than 45 cm/sec subsequently developed occlusion or were noted to have a severe associated stenosis. Six patients developed unheralded graft occlusion less than three months following determination of the graft flow velocity. Four of these patients (67%) had bypasses to the dorsalis pedis artery. Graft flow velocity measurements do not always predict an impending graft failure, and other factors may contribute to the sudden occlusion of patent distal bypasses, especially to the pedal arteries. Although the concept of hemodynamic monitoring to identify impending graft failure is an attractive one, more sensitive or refined measurements (especially to the pedal vessels), are required.
用于确定移植物血流速度的双功扫描是在下肢旁路移植物闭塞之前识别有失败风险的移植物的有效方法。我们实施了一项使用双功扫描的移植物监测方案，并在两年的时间间隔内，利用移植物血流速度、踝/臂指数和趾压测量对54条下肢旁路移植物进行了评估。确定有3例患者的移植物有血栓形成风险。在这些患者中，1例没有动脉造影狭窄的证据，1例患者有血流速度测量值降低的临床症状，1例患者的移植物在随访期间随后闭塞。8例移植物血流速度大于45 cm/秒的患者随后发生闭塞或被发现有严重的相关狭窄。6例患者在确定移植物血流速度后不到3个月出现意外的移植物闭塞。这些患者中有4例（67%）是足背动脉旁路移植。移植物血流速度测量并不总是能预测即将发生的移植物失败，其他因素可能导致通畅的远端旁路移植物突然闭塞，尤其是到足部动脉的旁路移植物。尽管通过血流动力学监测来识别即将发生的移植物失败这一概念很有吸引力，但仍需要更敏感或更精细的测量方法（尤其是针对足部血管）。
