Many surgical procedures are carried out with randomised trials to confirm their effectiveness. There is of course an ethical dilemma in performing placebo or sham surgery on patients. A sham treatment is a treatment or procedure that is performed as a control, and that is similar to but omits a key therapeutic element of the treatment or procedure under investigation. An example is where doctors may make an incision in a patient's skin over the knee to make it look like they have done real surgery, but don't do anything to the structures of the joint.

Example - Sham surgery for knee arthritis

Many procedures cannot be tested with sham surgery randomised trials as it would be unethical to not offer the real operation if some sort or procedure was necessarily need - e.g. for a broken leg.

One of the most important studies was back in 1959 by Leonard Cobb in the United States. This was published in the New England Journal of Medicine. This is before the days of coronary artery grafts (CAGs). In those days different procedures were tried to relieve angina.

Angina is lack of blood supply to heart muscle caused usually by narrowing of the coronary arteries. Because this is a very common problem, many different techniques were tried. One of these was the Fieschi technique.

This procedure was based on the assumption that if some arteries were tied off near the heart, more blood would flow through the narrowed coronary arteries. Doctors were not able to measure the blood flow in the arteries so it was impossible to test this objectively.

Because people were carrying out this surgery and patients were experiencing relief of their angina the procedure became very popular.

Dr Leonard Cobb studied this procedure in 17 patients who were scheduled to have the surgery. The patients were randomised into having the real operation, or just a skin incision to make it seem that they may have had the operation but without really having the operation. This was a real experimental trial and the patients did not know that they may be having fake or sham surgery!

They found that the same proportion in both groups had relief of their chest pain symptoms! In other words those who had no surgical procedure at all experienced relief of their chest pain at the same rate as those who had the real procedure.

Following that procedure the Fieschi procedure became very unpopular very quickly.

It is interesting to note that the effect that the patient's mind has on the ability to heal or experience improvement in symptoms. Other sham studies have been mentioned in the QOH Newsletters in the past as mentioned above.

It is worth noting that people who undergo surgery often have a high expectation of success and may overlook ongoing symptoms or modify their activities to achieve the expected relief from the procedure. The patient's belief that the surgery will be effective is a very powerful influence in whether they will recover. This is also the case for giving "placebo" medication or treatments. With placebos e.g. sugar pills, we expect about 30% of patients to get improvement. This is the so-called placebo effect and it has been very widely studied.

As such surgery isn’t magical but has a major impact on people and their belief in how their health may improve.

We will publish more in this area in future newsletters.

Other Newsletters: