TITLE: Maturation Rates of Arteriovenous Fistulas Using Small Veins in the Era of Endovascular Interventions.
BACKGROUND: Traditional practice suggests the abandonment of veins smaller than 3 mm in diameter for arteriovenous fistula (AVF) creation because of a low rate of maturation. This study aims to show that with balloon-assisted maturation (BAM), undersized veins can be used to create functional AVFs with a high rate of success.
METHODS: All patients who underwent AVF creation between 2014 and 2018 at a tertiary academic medical center were retrospectively reviewed. The patients without preoperative vein mapping, those who failed to follow-up, and the patients who were not on dialysis were excluded. A fistula was considered to be mature if it was successfully cannulated for dialysis. A total of 596 patients were identified for analysis. The cohort was divided into the small-vein group (SVG, <2.5 mm) and large-vein group (LVG, ≥2.5 mm) based on preoperative vein size. Categorical variables were analyzed with the chi-squared test for their association with maturation status. Continuous variables were analyzed with the Wilcoxon rank sum test. A P-value less than 0.05 was considered significant.
RESULTS: In the study cohort, 61.9% of the patients were male, with an average age of 62.8 ± 13.7 years, and an average preoperative vein size of 2.9 ± 1.1 mm. With similar demographic distribution, the participants in the SVG (n = 216) had significantly smaller preoperative vein size of 1.9 ± 0.4 mm than the patients in the LVG (n = 380), 3.5 ± 0.8 mm (P = 0.001). There were significantly more radio-cephalic AVFs created in the SVG (77.8% versus 48.7%, P < 0.0001). The overall maturation rate was 83.1% (n = 495), 219 fistulas (36.7%) matured primarily and 276 (46.3%) required interventions. Ninety-one percent of the patients required only 1 or 2 BAMs to achieve maturation. The SVG achieved a maturation rate of 75.9% as compared with 87.1% in the LVG (P = 0.002). A significantly higher number of patients in the SVG required BAM for maturation as compared with the LVG (67.7% versus 49.9%, P = 0.0002); however, there was no difference in the average number of BAMs required for fistula maturation between the groups (1.5 ± 0.8 for the SVG vs. 1.4 ± 0.7 for the LVG). In multivariable logistic regression analysis, vein size ≥2.5 mm (odds ratio (OR) = 2.11, confidence interval (CI): 1.36-3.27, P = 0.0009) and male sex (OR = 2.30, CI: 1.49-3.57, P = 0.0002) were independent predictors of maturation.
CONCLUSIONS: Small veins can be used for AVF creation with lower but still favorable maturation rates using BAM interventions, especially in male patients. This practice can increase the creation of autogenous dialysis access and potentially reduce complications related to prosthetic dialysis access.
SOURCE: Wang B, Rao A, Pappas K, et al. Maturation Rates of Arteriovenous Fistulas Using Small Veins in the Era of Endovascular Interventions[J]. Ann Vasc Surg, 2021, 71:208-214. DOI: 10.1016/j.avsg.2020.08.109.
背景：传统实践表明，由于成熟率低，因此放弃直径小于3 mm的静脉用于动静脉内瘘（AVF）的建立。这项研究旨在表明，通过球囊辅助成熟（BAM），可以使用较小尺寸的静脉来建立具有高成功率的功能性AVF。
方法：回顾性分析2014年至2018年在三级学术医学中心接受AVF建立的所有患者。术前未进行静脉造影的患者，随访失败的患者以及未接受透析的患者均被排除在外。如果成功穿刺进行透析，则认为内瘘已经成熟。总共确定了596例患者进行分析。根据术前静脉大小将队列分为小静脉组（SVG，<2.5 mm）和大静脉组（LVG，≥ 2.5 mm）。卡方检验分析了分类变量与成熟状态的关系。用Wilcoxon秩和检验分析连续变量。小于0.05的P值被认为是重要的。
结果：在该研究队列中，61.9％的患者为男性，平均年龄为62.8±13.7岁，术前平均静脉大小为2.9±1.1 mm。在人口分布相似的情况下，SVG（n = 216）的受试者术前静脉大小为1.9±0.4 mm，明显小于LVG( n = 380) 的患者3.5±0.8 mm (P = 0.001）。 SVG中产生的桡-头型AVF明显更多（77.8％ vs. 48.7％，P <0.0001）。总体成熟率为83.1％（n = 495），219例内瘘（36.7％）初次即成熟，而276例（46.3％）需要干预。 91％的患者仅需要1或2个BAM即可达到成熟。 SVG的成熟率为75.9％，而LVG的成熟率为87.1％（P = 0.002）。与LVG相比，SVG中需要BAM成熟的患者数量要高得多（67.7％ vs. 49.9％，P = 0.0002）；但是，两组之间内瘘成熟所需的平均BAM数量没有差异（SVG为1.5±0.8，LVG为1.4±0.7）。在多变量logistic回归分析中，静脉大小大于2.5mm（比值（OR）= 2.11，置信区间（CI）：1.36-3.27，P = 0.0009）和男性（OR = 2.30，CI：1.49-3.57，P = 0.0002） ）是成熟度的独立预测因子。
结论：通过BAM干预，小静脉可以较低但仍有利的成熟率用于AVF的建立，特别是在男性患者中。这种做法可以增加自体透析通路的建立，并可能减少与人造透析通路相关的并发症。
启发：通过球囊扩张方式，可促进小静脉内瘘的成熟，但仍需考虑动脉在成熟中所起的作用。2.5mm的静脉作为区分，对于国内来说，是否合适还需考究。
