背景:肝素粘结膨体聚四氟乙烯(He-ePTFE)导管是需要腹股沟下血运重建(iIR)的患者的一种选择,但是失败的风险可能是不可预测的,尤其是在径流差的情况下。术中传输时间流量(TTF)提供了流量的自动化和定量分析,并且可以在手术血运重建期间作为辅助评估。这项研究的目的是评估在三家转诊医院接受He-PTFEiIR的患者的TTF,并建立移植物闭塞的预测流量阈值。
方法:2020年启动的一项前瞻性注册登记,纳入了使用He-PTFE治疗严重肢体缺血或严重跛行的腹股沟下血运重建(iIR)患者,并对TTF测量进行了分析。所有患者均可进行术前解剖和临床特征评估。HT353Optima仪表(TransonicSystemsInc.,伊萨卡,NY,美国)根据标准化方案在所有程序中使用。机构伦理委员会批准了这项研究。使用受试者工作特征曲线(ROC)分析的预测模型用于建立流量阈值,和变量进行了比较。根据卢瑟福等级报告解剖学和临床评估,全球肢体解剖系统(GLASS)和伤口,缺血和足部感染(WIfI)分类。考虑的主要结果是TTF与移植物闭塞之间的相关性。次要结果包括生存率,移植物闭塞的其他预测因素,无重大不良心血管事件(MACE),免于严重截肢。
结果:在68例患者中,55.8%有卢瑟福5-6,45.6%有GLASS3,73.5%有WIfI3-4。远端吻合在胫骨水平占23.5%,导管平均直径为6.4mm。基础和术后TTF分别为27.8±15.6ml/min和109.0±53.0mil/min,分别。平均随访18±13个月后,7例(10.9%)患者出现移植物闭塞,5例(7.8%)需要大截肢。TTF阈值=80ml/min,其敏感性和特异性分别为81.8%(95CI48,2-97,7)和80.7%(95%CI68,1-90,0),并被选为移植物闭塞的截止值。TTF>80ml/min与TTF≤80ml/min的患者在6、12、24个月时的移植物闭塞自由度分别为95.7%(SE=0.030)和65.5%(SE=0.115),95.7%(SE=0.030)对58.9%(SE=0.120)和90.9%(SE=0.054)对51.6%(SE=0.126),p=0.0003。原发性通畅性无统计学差异,观察到二次通畅和保肢。在多变量分析中,胫骨血管远端吻合(OR8.50)和TTF≤80ml/min(OR9.39)是移植物闭塞的独立预测因子.
结论:这些结果表明,TTF可能是iIR管理的有价值的工具。TTF测量值≤80ml/min应视为移植物闭塞的预测因子。提示考虑额外的术中操作,以增加动脉流量。需要直接胫动脉血运重建的患者应谨慎行事,因为它代表独立于TTF水平的故障预测因子。需要更大的患者队列和更长的随访时间来确认这些发现。
BACKGROUND: The heparin-bonded expanded polytetrafluoroethylene (He-ePTFE) conduit is an option for patients requiring infrainguinal revascularization (iIR), but the risk of failure may be unpredictable, especially in cases with poor run-off. Intraoperative transit-time flow (TTF) provides an automated and quantitative analysis of flow and may serve as an adjunct evaluation during surgical revascularization. The aim of this study was to assess TTF in patients undergoing iIR with He-PTFE at 3 referral hospitals and to establish a predictive flow threshold for graft occlusion.
METHODS: A prospective registry initiated in 2020 enrolled patients undergoing iIR using He-PTFE for critical limb ischemia or severe claudication, and TTF measurement was analyzed. Preoperative assessments of anatomical and clinical characteristics were available for all patients. The HT353 Optima Meter (Transonic Systems Inc., Ithaca, NY, USA) was used in all procedures according to a standardized protocol. The institutional ethics committee approved the study. A predictive model using receiver operating characteristic curve analysis was utilized to establish the threshold of flow, and variables were compared. Anatomical and clinical evaluation were reported according to Rutherford grade, Global Limb Anatomic System and Wound, Ischemia, and foot Infection classification. The main outcome considered was the correlation between TTF and graft occlusion. Secondary outcomes included survival, other predictors of graft occlusion, freedom from major adverse cardiovascular events, and freedom from major amputation.
RESULTS: Among 68 patients, 55.8% had Rutherford 5-6, 45.6% had Global Limb Anatomic System 3 and 73.5% had Wound, Ischemia, and foot Infection 3-4. Distal anastomosis was at tibial level in 23.5% and mean diameter of conduit was 6.4 mm. Basal and postoperative TTF were 27.8 ± 15.6 ml/min and 109.0 ± 53.0 ml/min, respectively. After a mean follow-up of 18 ± 13 months, 7 (10.9%) patients presented graft occlusion and 5 (7.8%) required major amputation. TTF threshold = 80 ml/min revealed a sensitivity and specificity of 81.8% (95% confidence interval 48.2-97.7) and 80.7% (95% confidence interval 68.1-90.0) respectively, and it was selected as cut-off for graft occlusion. Freedom from graft occlusion in patients with TTF >80 ml/min vs. TTF ≤80 ml/min at 6, 12, and 24 months was 95.7% (standard error (SE) = 0.030) vs. 65.5% (SE = 0.115), 95.7% (SE = 0.030) vs. 58.9% (SE = 0.120) and 90.9% (SE = 0.054) vs. 51.6% (SE = 0.126), P = 0.0003. No statistical difference in primary patency, secondary patency and limb salvage was observed. At multivariate analysis, distal anastomosis at tibial vessel (odds ratio 8.50) and TTF ≤80 ml/min (odds ratio 9.39) were independent predictors of graft occlusion.
CONCLUSIONS: These results suggest that TTF may serve as a valuable tool in the management of iIR. A TTF measurement of ≤80 ml/min should be regarded as a predictor of graft occlusion, prompting consideration of additional intraoperative maneuvers to enhance arterial flow. Caution should be exercised in patients requiring direct tibial artery revascularization, as it represents a predictor of failure independent of TTF levels. Larger cohorts of patients and longer follow-up periods are necessary to confirm these findings.