Lower limb surveillance following autologous vein bypass should be life long

BACKGROUND

The aim of the study was to investigate whether infrainguinal vein graft surveillance can be stopped at 1 year without prejudicing graft or leg survival.

METHODS

Data were collected prospectively on 351 infrainguinal vein bypass grafts (326 patients) that had been entered into a vein graft surveillance programme between 1988 and 1997.

RESULTS

Some 104 grafts (30 per cent) developed significant new vein graft stenoses, 95 (91 per cent) of which occurred within 12 months. After 1 year, the risk of developing a significant graft stenosis was 3 per cent per year. Sixty-nine grafted limbs (20 per cent) developed new arterial inflow or run-off stenoses that required intervention, but only 37 (54 per cent) occurred within the first year, after which the risk was 9 per cent per year. The overall risk of developing a new vein graft or arterial stenosis after 1 year was 10 per cent per year.

CONCLUSION

The incidence of vein graft stenosis decreases significantly 1 year after operation but there is still at risk of developing potentially graft-threatening arterial stenoses. Legs that have undergone infrainguinal vein bypass grafting should continue to be monitored in a surveillance programme for life.

Predischarge duplex imaging of infrainguinal vein grafts does not predict the development of stenoses

BACKGROUND

The aim of this study was to determine whether predischarge duplex imaging of an infrainguinal vein graft could predict the subsequent development of graft stenosis.

METHODS

Patients with infrainguinal vein grafts underwent a duplex scan of the entire graft before discharge from hospital. Grafts were classified as abnormal or normal based on the presence or absence of flow abnormalities (peak velocity ratio 1.5 or greater). All grafts were re-examined 1 month after surgery, at 3-monthly intervals for the first year and then every 6 months thereafter. A significant stenosis requiring correction was defined by a duplex-derived peak systolic velocity ratio of 3.0 or more. The relationship between the predischarge scan and subsequent development of stenosis was examined.

RESULTS

Forty-four grafts were recruited. Two occluded soon after a normal predischarge scan and were excluded from subsequent analysis. Predischarge abnormalities were found in 16 grafts. The abnormality in one graft required immediate correction. A further four grafts subsequently developed significant stenoses and required angioplasty. Of the 26 grafts with no predischarge abnormalities, 11 developed significant stenoses and underwent angioplasty. Abnormal predischarge duplex scans had a sensitivity and specificity of 31 and 58 per cent respectively for the development of stenoses. The positive and negative predictive values were 31 and 58 per cent respectively.

CONCLUSION

Predischarge duplex imaging cannot be used to predict the development of stenoses in infrainguinal vein grafts.