When is a technically successful peripheral angioplasty effective in preventing above-the-ankle amputation in diabetic patients with critical limb ischaemia?

AIM: To determine parameters predictive of avoidance of major (above-the-ankle) amputation after a technically successful peripheral angioplasty (PTA) in patients with diabetes with critical limb ischaemia.
METHODS: From January 1999 to December 2003, 420 consecutive patients with diabetes admitted to hospital because of critical limb ischaemia underwent peripheral angiography and concomitant technically successful PTA. Transcutaneous oxygen tension (TcPO(2)) was measured before and after PTA. Major amputation at 30 days was recorded.
RESULTS: After PTA, the iliac-femoral-popliteal axis was patent in all patients. In 67 patients, all three crural arteries were patent, in 143 patients 2 crural arteries were patent, and in 186 patients one crural artery was patent (104 peroneal, 62 anterior tibial, 20 posterior tibial). In 24 patients, all three crural arteries were occluded. Twenty-two major amputations were performed. Of these, 15 were performed in the 24 patients with occlusion of all the infrapopliteal arteries. Seven of the 186 patients in whom only the peroneal artery was patent required amputation. In patients not requiring amputation, TcPO(2) increased from 15.5 +/- 11.9 to 45.0 +/- 12.0 mmHg (P = 0.000), while in those requiring amputation, TcPO(2) increased from 9.6 +/- 7.7 to 18.6 +/- 8.1 mmHg (P < 0.082). Multivariate analysis indicated an independent role of occlusion of infrapopliteal arteries after PTA (OR 8.20 for every crural obstructed artery, P = 0.022, CI 1.35-49.6) and TcPO(2) after PTA (OR 0.80 for increase of 1 mmHg, P < 0.001, CI 0.74-0.88).
CONCLUSIONS: In patients with diabetes, PTA is effective in avoiding major amputation, provided recanalization occurs in at least one tibial artery down to the foot. In a few patients, re-canalization of the peroneal artery alone is not sufficient to avoid major amputation.