Determination of amputation level in ischaemic lower limbs

A properly performed amputation can not only be lifesaving for the patient, but may often be a better therapeutic alternative than an ill-conceived, futile attempt at a vascular reconstruction doomed to fail for lack of adequate recipient vessels. Currently there are no consistent criteria that can be applied before surgery. The purpose of the present investigation was to find a reliable method of determining the best amputation level in an ischaemic lower extremity.

In the present study the author has tried to devise a 'score' for distal run-off vessel patency as shown by the preoperative angiogram to determine the most appropriate amputation level. The author has reviewed the level of amputation on ischaemic lower extremities in the vascular surgery unit of the Austin and Repatriation Medical Centre (ARMC) over the last 5 years. Two hundred and two patients have undergone 232 lower extremity amputations at ARMC.

The author used chi2 corrected testing and found a good correlation between the score and the level of amputation. The lower the score, the higher the level of amputations (chi2 = 289.23, P < 0.005). The author could predict that with a score of <12 a patient would probably need an above-knee amputation; for a score from 12 to 19, a below-knee amputation; for a score of 20-25 a forefoot amputation would be sufficient and for a score of>25 a toe amputation would be all that was required.

The use of a scoring system dependent on the preoperative angiogram to assess the run-off vessel situation provides a practicable and direct way to help predict the level of amputation in an ischaemic lower extremity. However, it is not totally reliable and should be used as one of the factors to be considered when an amputation is required.