Factors Predicting the Outcome of Intraarterial Thrombolysis in Peripheral Arterial and Graft Occlusions

The Outcome of Occluded Above-knee Femoropopliteal Prostheses Implanted for Critical Ischaemia

OBJECTIVES

To investigate the impact of patient characteristics and treatment modality (graft thrombectomy vs thrombolysis) on the results of redo procedures for occluded above-knee prosthetic femoropopliteal grafts implanted for critical ischaemia.

MATERIAL AND METHODS

Fifty-five procedures (thrombolysis 24 and thrombectomy 31) were performed on 24 prostheses (23 patients, 24 limbs) between January 1990 and December 2001. All cases were prospectively registered. Graft patency, limb salvage and survival rates were studied and subgroups of patients were compared. Risk factors were analysed with the use of log rank test and Cox proportional hazard analysis.

RESULTS

Half of the 24 initial procedures to restored patency failed within one month. The outcome of second- or third-time redo procedures was similar. The primary patency rates of all 55 redo procedures were 32% at three months, 28% at six months and 12% at 12 months. The results of thrombectomy and thrombolysis were similar. Re-opened grafts additionally treated for an underlying anastomotic stenosis had significantly better patency as compared with re-opened grafts without a pre-existing stenosis on both univariate analysis (p = 0.024) and multivariate analysis (p = 0.027, hazard ratio 2.813). The one-year limb salvage rate was 76%. The one- and five-year survival rates were 87% and 52%, respectively.

CONCLUSIONS

The results of redo procedures for occluded above-knee prosthetic grafts were disappointing. Grafts in which a graft-related stenosis was treated performed better than grafts in which occlusion could not be attributed to an underlying stenosis. Such cases should most likely be offered conservative treatment, amputation or a new arterial reconstruction.

Predictive Factors for the Removal of "Soft" Femoropopliteal Occlusions with Intraarterial Short-term and High-Dose Urokinase Treatment

To date, intraarterial lysis is a widely accepted form of treatment for femoropopliteal occlusions. However, the outcome of therapy has been difficult to predict. Therefore, the present study dealt with two parameters likely to influence the occlusion removal rate. These are the outflow condition distal of the occlusion, and the occlusion length. Fifty patients with subacute femoropopliteal occlusions were treated with intraarterial thrombolysis and, in case residual obstructions were left, with subsequent catheter dilation. Only "soft" occlusions that were probed by a guide wire and proved to be penetrable were chosen for treatment. The occlusion age was 3.79 +/- 4.57 weeks with 90% of cases in the range of 1 day to 6 weeks. Fibrinolytic therapy consisted of one to three one-hour series of 300,000 IU urokinase instillation directly into the occlusion material. The complete clearance rate was 34/50 = 68%. In successfully treated patients, both the pressure gradient (difference between systemic and ankle pressure) and the walking distance improved significantly. Most important factors for success or failure of treatment were the quality of calf outflow and the length of obstruction. Thus, patients with at least one calf artery open and an occlusion length of under 10 cm presented with an opening rate of 88.5%, whereas patients with no calf arteries patent and an occlusion length over 20 cm presented with an opening rate of only 20%. The age of the occlusions, all penetrable by a guide wire prior to treatment, did not influence the rate of recanalization. Intraarterial short-term and high-dose urokinase infusion is an excellent form of treatment for subacute femoropopliteal occlusions. Especially good results with a 88.5% clearance rate were achieved in patients who presented with at least one calf artery open and an occlusion length below 10 cm.