HERNIA INSTITUTE OF PENNSYLVANIA

THE MYOPECTINEAL ORIFICE
of Fruchaud
Presented by
The North Penn Hernia Insitute
North Penn Hernia Institute Logo
NATIONAL HERNIA CENTER
EXCELLENCE IN ADVANCED HERNIA SURGERY

This is a sketch of the hernia-vulnerable area of the Right groin (the egg-shaped region near the center of the drawing), which is called the Myopectineal Orifice of Fruchaud (MPO).
Note specifically that the MPO is neither fully nor efficiently covered nor reinforced by muscle layers. The MPO is simply a layer of non-muscular Connective Tissue called "Transversalis Fascia", consisting of two thin and adherent semi-layers. The MPO is bordered:
  • Above by the arching fibers of the internal oblique and transversus abdominus Muscles, (a.k.a. Conjoined Tendon)
  • Medially (towards the center or to the right) by the Rectus Abdominus Muscle and its fascial Rectus Sheath,
  • Inferiorly by Coopers Ligament, and
  • Laterally by the Ileopsoas Muscle.
The structure running through the center of the MPO, from end to end, is the Inguinal Ligament, and it runs from the anterior-superior iliac spine (on the left of the photo) to the pubic tubercle. The oval structure in the upper half of the MPO represents the Internal Inguinal Ring (Site of Congenital or Indirect Hernias).

It is through the internal ring that the structures of the spermatic cord (vas defrens and vessels) penetrate the abdominal wall, coursing downward and centrally through the inguinal canal towards the scrotum. It is also through this internal ring that an Indirect Inguinal Hernia will protrude, widening the ring as it progressively enlarges. To the right of (medial to) the internal ring, is the area of the MPO known as the Medial Triangle (AKA, Direct Space, Hesselbach's Triangle, Hessert's Triangle and Floor of the Inguinal Canal). This is the location through which a "Direct Hernia" develops. Below the Inguinal Ligament lies the portion of the MPO called the Femoral Triangle. On the right side of this area are the two vessels (Femoral artery to your left and Femoral Vein on the right, or the most medially of the two vessels) which are majorly repsonsible for the blood supply to and from the leg. To the left of these vessels (towards the pubic tubercle) lies the Femoral Canal, a thinned and weakend area of Transcersalis Fascia through which Femoral Hernias develop (more common in females because due to the pelvic shape, this area is larger in females than in males). This entire MPO is vulnerable to the development of hernias, partially because of
  • The normal congenital/anatomic gaps that occur in it (i.e., Internal Ring)
  • Significantly because it is not reinforced by adequate muscle layers as is the remainder of the abdominal wall, and
  • Probably in many patients because of an underlying Connective Tissue Disorder (let's call it "Herniosis") which makes the non-reinforced Transversalis Fascia weaker and less able to resist the repetitive intra-abdominal pressure stresses placed upon it leading to progressive bulging, weakness and hernia formation.
Thus an Inguinal "Hernia" is really a Pathologic Hole or Defect within the Transversalis Fascia, that occurs specifically within the area of a poorly reinforced and therefore hernia prone anatomic hole, which is called the MYOPECTINEAL ORIFICE.
Now lets think of the MPO like a 'frozen lake' (photo at left) at the center of which is a puddle (or Hole) in the ice. Think of a hernia as a 'Hole' in the ice on a frozen lake. Many surgeons' concept of a hernia is simply this, a HOLE in the abdominal wall that must be addressed (i.e., plug it up or sew it closed and that's that!!). But look closely at the Photo. The Puddle, or "Hole", is surrounded by an area of "THIN ICE". So too, a hernia, be it direct or indirect or even femoral, cannot be considered simply as the visable hole. It is always surrounded by an area of weakened, thinned-out, clinically significant and more likely hernia-prone fascia: This is the entire Transversalis Fascia of the MPO.

It is not only the area of the "HOLE" that must be repaired, but the
"WHOLE AREA".


Failure to adequately address the "WHOLE" hernia-prone area of the groin with full reinforcement of the entire MPO, in a true Tension-Free fashion, is the principle and predominent cause of hernia recurrences. We believe that any additional hernia in the region of the Myopectineal Orifice at any time following a prior repair is a Recurrent Hernia, even if not in the exact area of the initial or primary defect.

In order to effectively repair an Inguinal Hernia, we strongly believe that this entire area the MPO, MUST also be reinforced. If you only address the HOLE, the surrounding area will be subjected to a 'Pressure Imbalance' whereby normal and at times increased intra-abdominal pressure, now buttressed at the 'hole' will exert a deleterious effect on the surrounding Transversalis Fascia elsewhere in the MPO. Most recurrent hernias are not at the site of the initial repair, but rather adjacent to it, on the THIN ICE area of the weakened and ineffectively reinforced MPO.

Physiologically, the best place to reinforce the MPO is behind the Transversalis Fascia where it will lie securely between tissue layers (between the peritoneum and the under-surface of the Transversalis Fascia), being secured by tissue pressure on each side (like a leaf pressed within the pages of a book). It is like the difference between patching a flat tire with a patch on the inside of the tire (i.e., under the Transversalis Fascia), or just placing the patch on the outside of the tire and driving off down the road. Placing simply an overlay mesh, oten too small to fully cover the MPO anyway, (with or without a plug in the hole) risks intra-abdominal pressure lifting the mesh up and off of the MPO as the weakened Transversalis Fascia continues to weaken, resulting in a recurrent hernia.
YOU MUST REINFORCE THE "WHOLE", and NOT JUST PATCH or PLUG THE 'HOLE'!