Noninvasive measurement of ambulatory venous pressure via column interruption duration in chronic venous disease

BackgroundColumn interruption duration (CID) is a non-invasive surrogate for venous refill time (VFT), a parameter used in ambulatory venous pressure measurement. CID is more accurate than invasive VFT measurement because it avoids errors involved with indirect access of the deep system through the dorsal foot vein. The aim of this retrospective single center study is to analyze the clinical usefulness of CID in assessment of chronic venous disease (CVD).MethodsPatients & subjectsA total of 1551 limbs (777 patients) were referred with CVD symptoms over a 5-year period (2018-2023); CID, Air plethysmography (APG) and duplex reflux data were analyzed. 679 of these limbs had supine venous pressure data as well.The pathology was categorized as obstruction if supine peripheral venous pressure was >11 mm Hg. and as reflux if Duplex reflux time in superficial or deep veins was >1sec. CID was measured via doppler monitoring of flow in the great saphenous vein (GSV) and one of the paired posterior tibial veins (PT) near the ankle in the erect posture. The calf is emptied by rapid inflation cuff. CID is the time interval in seconds when cephalad venous flow in GSV and PT reappear after calf ejection. A CID <20 sec. in either vein is abnormal similar to the threshold used in VFT measurement.Results32% of the limbs had obstruction, 17% had reflux and 37% had a combination; 14% had neither. Higher CEAP clinical classes (C4-6) were prevalent in 44% of pure reflux, significantly less (p<0.0001) than in pure obstruction (73%) or obstruction plus reflux subsets (72%), partly reflecting distribution of pathology. There is a progressive increase in supine venous pressure and abnormal CID (p<0.0001and p<0.0001respectively) in successive CEAP clinical class. No such correlation between CEAP and any of the reflux severity grading methods (reflux segment score, VFI90 and Kistner axial grading) was observed. Abnormal CID (55%) was more prevalent in higher CEAP classes (>4) (p<0.0001) than in lesser clinical classes (0-2) or limbs with neither obstruction nor reflux (p=0.0093).ConclusionObstruction appears to be a more dominant pathology in clinical progression among CEAP clinical classes than reflux. CID is abnormal in both obstructive and refluxive pathologies and may represent a common end pathway for similar clinical manifestations (eg. Ulcer). These data suggest a useful role for CID measurement in clinical assessment of CVD limbs.