A solution to ankle-brachial index limitations in peripheral transluminal angioplasty.

PURPOSE

We evaluated the limitations of the ankle-brachial index (ABI) in the revascularisation of diabetic patients with critical limb ischaemia (CLI) who were undergoing peripheral transluminal angioplasty (PTA) compared with the degree of arterial stenosis and with transcutaneous oxygen tension (TcpO2).

MATERIALS AND METHODS

This prospective study assessed 250 consecutive diabetic patients in whom we evaluated results of posterior tibial and dorsalis pedis Doppler, ABI, TcpO2, and duplex scans. In total, 104 patients were considered suitable candidates for PTA.

RESULTS

In 42% of the patients studied, ABI could either not be used (9.34% due to no signal; 14.02% because the artery could not be compressed) or was incorrect (18.7% before PTA; 15.9% after PTA). In contrast, TcpO2 was determined in all cases. After PTA, vessel stenosis decreased from 58.33±20.07% to 21.87±13.57% (p<0.001), whereas ABI increased from 0.79±0.57 to 0.95±0.47 (p<0.001) and TcpO2 from 27.37±10.40 mmHg to 38.23±10.25 mmHg (p<0.001). A statistical analysis revealed scant correlation between techniques (TcpO2 and ABI) (r=0.14).

CONCLUSIONS

ABI shows significant limitations for the diagnosing and treating CLI patients compared with TcpO2.