The nature and importance of changes in toe-brachial pressure indices following percutaneous transluminal angioplasty for leg ischaemia.

OBJECTIVES

To document changes in toe-brachial pressure indices (TBPI) during the 6 months following percutaneous transluminal angioplasty (PTA) and relate these changes to restenosis. Furthermore, to ascertain the effect of administering a vasodilator, glyceryl trinitrate (GTN), immediately following PTA.

DESIGN

Eighty-three technically successful PTA procedures were studied. Fifty-six were for intermittent claudication, 14 for ischaemic rest pain, and 13 for non-healing ulcers. Immediately following balloon dilatation an intra-arterial bolus of either 150 micrograms GTN, with or without a 10 mg GTN patch for 24 h, or a saline placebo was administered. TBPI were measured before and for 6 h after PTA and then at 24 h, 1 week, 1 month and 6 months. At this time, patency at the PTA site was determined by arteriography.

RESULTS

There was continuing TBPI improvement over 1 month in patients given saline following PTA. In patients given GTN, peak TBPI was achieved by 1 week, and corresponded with the TBPI observed immediately following GTN administration. Restenosis occurred in 27 (33%) patients, and was significantly more frequent following the procedures for rest pain or ulceration, or where a TBPI increase of more than 0.15 by 1 week was observed.

CONCLUSIONS

Haemodynamic changes following PTA continue for at least 1 month, can be modified by GTN administration, and are predictive of subsequent restenosis. Measuring the TBPI increase during the first week following PTA underestimates total improvement, and may give false reassurance with respect to recurrent disease.