Lattimer C R, Azzam M, Kalodiki E, Geroulakos G
Ealing Hospital & Imperial College, London SW7 2AZ, UK.
Phlebology. 2014 Mar;29(2):90-7. doi: 10.1258/phleb.2012.012042. Epub 2013 May 6.
Venous filling time (VFT90) is the time taken to reach 90% of the venous volume in the calf. It is recorded by air-plethysmography (APG(®)) and is assumed to measure global venous reflux duration. However, this has never been confirmed by duplex. The aim of the study was to compare VFT on APG to venous reflux time/duration (RT) measured simultaneously with duplex on the same patients.
Twenty-six consecutive patients, M:F = 16:10, age (25-78), C1 = 1, C2 = 4, C3 = 8, C4a = 6, C4b = 4, C5 = 2, C6 = 1, underwent simultaneous APG with duplex. The venous filling index (VFI, mL/second), VFT90 (seconds), great saphenous vein (GSV) RT on duplex, averaged thigh GSV diameter and thigh length (length) between the APG sensor air-cuff and duplex transducer were recorded. The VFT100 was calculated by VFT90/0.9. The additional time taken to fill the thigh was achieved using the VFI, length and deep vein diameter (d), to determine the corrected reflux duration: CRD = VFT100 + (length × πd(2)/4 (1/VFI)).
Twenty-five patients are presented. One patient with very mild reflux (VFT90 = 55.9 seconds) had an indeterminate endpoint on duplex and was excluded. The median (range) VFI and GSV diameter was 4.9(1.3-15.5) mL/second and 7(4-17) mm, respectively. The VFT90 and VFT100 both correlated with RT on duplex (Spearman, P < 0.0005) at: r = 0.933, r(2) linear = 0.72 and r = 0.933, r(2) linear = 0.68, respectively. The median (interquartile range) filling time with VFT90 was less than the duplex RT at 24 (16.9) versus 28 (20) seconds respectively, P < 0.0005 (Wilcoxon). The median percentage underestimation improved from 24% to 16% and then 4% using the VFT90, VFT100 and CRD, respectively.
This is the first study to compare APG parameters with duplex by performing simultaneous measurements. There was an excellent correlation between the VFT90 versus duplex RT, thereby comparing reverse flow in a single superficial vein against the legs overall venous haemodynamic status. These tests can both be used in the quantification of reflux.
静脉充盈时间（VFT90）是小腿静脉容积达到90%所需的时间。它通过空气容积描记法（APG(®)）记录，并被认为可测量整体静脉反流持续时间。然而，这从未通过双功超声得到证实。本研究的目的是比较APG上的VFT与在同一患者身上同时用双功超声测量的静脉反流时间/持续时间（RT）。
连续纳入26例患者，男:女 = 16:10，年龄（25 - 78岁），C1 = 1例，C2 = 4例，C3 = 8例，C4a = 6例，C4b = 4例，C5 = 2例，C6 = 1例，同时进行APG和双功超声检查。记录静脉充盈指数（VFI，毫升/秒）、VFT90（秒）、双功超声上大隐静脉（GSV）的RT、APG传感器气袖与双功超声换能器之间大腿GSV的平均直径和大腿长度（长度）。VFT100通过VFT90/0.9计算得出。使用VFI、长度和深静脉直径（d）来确定填充大腿所需的额外时间，以计算校正反流持续时间：CRD = VFT100 +（长度×πd²/4（1/VFI））。
呈现25例患者的数据。1例反流非常轻微（VFT90 = 55.9秒）的患者在双功超声检查中有不确定的终点，被排除。VFI和GSV直径的中位数（范围）分别为4.9（1.3 - 15.5）毫升/秒和7（4 - 17）毫米。VFT90和VFT100与双功超声上的RT均呈相关性（Spearman检验，P < 0.0005），相关系数分别为：r = 0.933，线性r² = 0.72以及r = 0.933，线性r² = 0.68。VFT90的中位数（四分位间距）充盈时间短于双功超声的RT，分别为24（16.9）秒和28（20）秒，P < 0.0005（Wilcoxon检验）。使用VFT90、VFT100和CRD时，低估的中位数百分比分别从24%改善至16%，然后降至4%。
这是第一项通过同时测量来比较APG参数与双功超声的研究。VFT90与双功超声RT之间存在极好的相关性，从而将单一浅静脉的逆流与腿部整体静脉血流动力学状态进行了比较。这两种检查均可用于反流的定量分析。
