- See:
- diabetic foot menu
- amputation menu
- osteomyelitis in the diabetic patient
- Discussion:
- amputation should be considered for any diabetic patient w/ advanced changes (Charcot joints, multiple ulcers, vascular pathology) who has who has undergone a surgical debridement which could not logically leave the patient w/ a functional foot;
- vascular considerations:
- exam:
- it is essential to distinguish between proximal and distal vascular lesions, since distal vascular lesions may be less amenable to arterial bypass (this statement is restricted to the diabetic patient w/ ischemic ulcerations or osteomyelitis);
- if there is an iliac pulse but no popliteal pulse (proximal lesion) then the patient should under go a formal vascular work up (since vascular bypass may be possible);
- if there is a popliteal pulse but no DP or PT pulse (distal lesion), then it is less likely that a vascular bypass will be successful);
- these patients should still have a vascular workup;
- doppler ABI:
- in most cases, serves no useful role in the management of diabetic feet;
- the loss of compliance of the diabetic vessels will falsely elevate ABI readings, (which may falsely indicate that the diabetic foot is well perfused);
- references:
- Arterial systolic pressures in critical ischemia.
- Prognostic value of systolic ankle and toe blood pressure levels in outcome of diabetic foot ulcer.
- Transcutaneous Doppler ultrasound in the prediction of healing and the selection of surgical level for dysvascular lesions of the toes and forefoot.
- Doppler-determined segmental pressures and wound-healing in amputations for vascular disease.
- An index of healing in below-knee amputation: leg blood pressure by Doppler ultrasound.
- transcutaneous O2:
- references:
- Transcutaneous oxygen as a predictor of wound healing in amputations of the foot and ankle.
- Segmental transcutaneous measurements of PO2 in patients requiring below the-knee amputation for peripheral vascular insufficiency.
- Transcutaneous oxygen tension measurement in peripheral vascular disease.
- Transcutaneous oxygen and carbon dioxide pressure monitoring to determine severity of limb ischemia and to predict surgical outcome.
- Surgical Considerations:
- often diabetic patients do not do well w/ transmetatarsal amputations, but this procedure may be indicated for wet gangrene involving the great toe and multiple lesser toes;
- if there is any debate as to whether a distal foot amputation will heal, then the surgeon can start out w/ the distal amputation and can assess the adequacy of bleeding at that time;
- needle test:
- this can be used to help determine the level of amputation once the patient is under anesthesia;
- prick the patient's thigh w/ a 20 gauge needle and assess the rate of bleeding;
- then sequentially prick the patient's foot, ankle, and calf and compare the bleeding to the control;
- patients with wet gangrene of the foot should be treated w/ open amputation just above or thru the ankle;
- once the sepsis has cleared, a definative BKA can be performed;
- it is generally a mistake to perform an open amputation at the same level as is planed for the definative amputation;
- references:
Simplified two-stage below-knee amputation for unsalvageable diabetic foot infections.
Syme amputation in patients with severe diabetes mellitus.
Lower-limb Amputations in Patients With Diabetes Mellitus
The diabetic foot: evolving technologies.
Management of the diabetic foot.
One-stage versus two-stage amputation for wet gangrene of the lower extremity: a randomized study.
Diabetic foot infections. Bacteriologic analysis.
Simplified two-stage below-knee amputation for unsalvageable diabetic foot infections.
Long term prognosis after healed amputation in patients with diabetes.