Animated at right:
Open MRI provides
the necessary accuracy and reliability to safely inject
the piriformis muscle with therapeutic and diagnostic
agents
The piriformis muscle is a relatively
small structure located as far as eight inches below
the surface of the buttock. If a blind injection misses
the muscle, the injection test is meaningless. Immediately
deep to the piriformis muscle is the sciatic nerve
and the colon so misplacement of the needle may lead
to significant complications.
Dr. Aaron Filler's use of Open
MRI image guidance makes this a safe, reliable and
accurate procedure. In these images, the physician's
finger is seen indicating the angle of approach in
the first image. In subsequent views, local anesthetic
is injected in the skin and then a titanium Lufkin
needle is introduced and advanced into the piriformis
muscle. An injection of Marcaine (10cc of 0.5% solution
of this long-acting local anesthetic) and Celestone
(1cc of this steroid medication) is then seen darkening
the interior of the muscle in the last two image frames.
These flash MRI images each take
about 12 seconds to complete. In about 20% of cases
the injection is therapeutic and the piriformis syndrome
resolves completely and permanently. In others, the
injection needs to repeated in a few months, and in
still others, it last only a few days. In this category,
surgery may be required to maintain the pain relief.
Thanks to Dr. Filler's minimal
access technique, piriformis surgery is now a small
procedure which can be carried out under local anesthetic
as an outpatient.
