Critique of Tension Free
The abdomen is a pressurized elastic container. Wall tension of
this container is described by the Laplace Equation:
T = P•R
is wall tension, P
interior pressure and R
is the radius of curvature
of the wall.
No where in the abdominal wall does wall tension
equal zero because nowhere in the abdomen does P equal zero, except
when the patient is asleep. But this a trivial situation which has
no meaning in real life.
This common misunderstanding is used
to sell mesh. When mesh is placed and the patient is asleep there is
no tension. After the operation when the patient is awake it is a
completely different situation. Mesh is effective only in as much as
it bears tension. Mesh seals itself to the tissue that it supports
by inciting chronic inflammation. This chronic inflammation never
stops. In 20% of patients this chronic inflammation results in
chronic pain which also never stops. Proponents of mesh say
that their recurrence rates are less than 1/2% as if that is all
that matters. Chronic pain that occurs in as many as 20% is a
serious problem which is not justified by an absolute difference of
2% in recurrences. It is faulty thinking that is unbecoming of our
Proponents of mesh also refer to non-mesh repairs
as old fashion tension repairs. We have had mesh since it was first
patented in 1954. For decades there was very little interest in it
until the early 1990's when manufactures found a way to effectively
market it. They got famous surgeons who were recieving royalities
from the manufacturers to call it "The Standard of Care" essentially
telling all other surgeons that the debate was over and that
everyone should fall in line or risk being accused of not practicing
the standard of care. This surgeon bristled at being told that his
tried and true technique should be abandoned in favor of putting an
untested synthetic material into his patients for at best a minor
reduction in recurrence and at worst no one knew. We now know
chronic pain is the problem. Chronic pain was not reported in the
medical literature and recognised as a real problem until 1998.
Before that time mesh ascended to the standard of care and now there
are very few surgeons who know how to effectively repair a hernia
without mesh. It is a dysfunctional situation which is perpetuated
by big money.
One of the problems with mesh is that it’s
properties of elasticity and compliance poorly match natural tissue.
That is, it does not bear tension like natural tissue. This mismatch
of mechanical properties causes stress and is one of the mechanisms
by which mesh causes chronic pain. Also stress at the mesh–tissue
boundary causes tissue disruption leading to a new hernia.
Imagine fixing a bicycle inner tube hole with a steel patch. The
patch will never fail but the rubber inner tube will not bear the
patch. The best patch for an inner tube is a rubber patch that
matches the properties of the inner tube.. If it could be preformed
the best repair would be to restore the defect. This is the
principle of a non-mesh hernia repair.
The most ideal hernia
repair restores the defect without changing anatomy or physiology.
This is the principle of a transversalis based repair such as the
Basinni, the McVay and the Shouldice. The so called tension free
repairs are not tension free in reality. They obliterate anatomy and
massively distort normal physiology.