Sunday, July 8, 2007

Modern Medicine

Vascular Surgery
Week 3

This week I’ll outline two procedures I saw that bookend modern medicine: the guillotine amputation and the arteriovenous fistula.

The Guillotine Amputation

This is a guillotine amputation. Like its name implies, this type of amputation is performed by cutting linearly through, and perpendicular to, the long axis of a limb. It’s used in emergency situations for quick removal of malignant infection. It’s also called a “flapless” amputation because no tissue is left to cover the stump. The wound is dressed but left open to avoid new infection until a proper amputation can be performed when the patient is more stable. This picture shows a transtibial amputation with the distal tibia and fibula in the stump end.

I got a first-hand view of this amputation as I held the patient’s stump while the surgeon wrapped the wound. Needless to say, this condition is as painful as it looks. This procedure is the same one that was used on the battlefields of the American Civil War nearly 150 years ago.

The Arteriovenous Fistula

As I mentioned previously, the AV fistula is the joining of an artery to a vein. This has the effect of increasing blood flow to the vein and can be felt as a vibration or “thrill” when the anastamosis under the skin is palpated (think of a cat purring). In response to the increased blood flow, the vein stretches and remodels to become stronger. This is called maturing, and after 3-6 months the vein will increase in size and look like a cord under the skin. This is an important procedure for dialysis patients—once mature, the fistula is strong enough to facilitate the insertion of the large needles needed for dialysis. This was a fantastic procedure to see—the surgeon opens the arm and literally sews an artery to a vein.

The guillotine amputation is crude and primitive and the AV fistula is complex and requires significant technological advancement, but both techniques currently classify as modern medicine.

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