Case:
41 year old woman with a history of an abdominal myomectomy followed by a pregnancy, ending in cesarean delivery. Over time a firm mass could be felt in the abdominal wall which was swollen with her menses. She had been seen by several physicians who were unable to clearly diagnose the mass. She eventually was diagnosed by a new PCP, and was referred to our office for treatment.
On being seen in our office, we ordered and reviewed MRI images, which demonstrated abdominal wall endometriosis replacing a large segment of the left rectus abdominus muscle and overlying fascia.
These images demonstrated the mass to be approximately 4 x 3 cm in size, with marked gadolinium enhancement in several areas.
A plan was made to do a laparotomy, with expectation that after removal there would be a significant defect in the fascia, likely requiring mesh repair.
At laparotomy, the mass was clearly palpable just under the subcutaneous fat. The mass was grasped with a towel clamp and pulled forward, with electrocautery used to dissect away the interface between the mass and surrounding fat.
Dissection through the rectus fascia was required to come around the mass, exposing portions of the rectus abdominus muscle:
One can see here the left edge of the unaffected rectus muscle and its interface with the diseased tissue
The mass was pulled inferiorly after separating the fascia above it. The cut edge of the fascia is seen in the Allis clamp at the top of the image, with the mass pulled inferiorly.
We now have come under the mass, and found the entire rectus muscle gone at this location, with the dissection leading into the Space of Retzius and with the retroperitoneal bladder dome exposed.
Finally excised, the masss measured approx 5 cm in width with surrounding inflammatory tissue and a margin of healthy tissue.
Following excision, there was an 8 x 10 cm defect in the rectus fascia, with exposed bladder and cut edges of the left rectus abdominus muscle.
As the rectus fascia could not be reapproximated without tension, a decision was made to perform a mesh reconstruction. A plane beneath the muscle in the pre-periteneal space was developed, contiguous with the retropubic space. A 8 x 10 lightweight polypropylene mesh was anchored inferiorly to Cooper’s ligaments bilaterally.
The mesh was anchored laterally underneath the residual rectus muscles, with sutures through and through muscle and through the lateral mid portion of the mesh. Of note, the suture anchors were not at the edges of the mesh but rather approx 2 cm from the edge of the mesh, to create an overlapping between the mesh edges and the fascial defect.
The superior fascial edge was pulled down over the super edge of the mesh, as far as could be without creating undue tension.
The remnant rectus muscle was sutured over the mesh, in order to maximize tissue between the mesh and skin closure, as well as to decrease potential for seroma formation.
With the muscle approximated over the mesh, the subcutaneous space was closed with suture followed by a skin closure.
It is the expectation that this surgery will dramatically if not completely rid the patient of her severe abdominal wall pain, and with rest and healing the mesh repair should be durable. The loss of a portion of the rectus abdominus muscle should not lead to substantial functional deficit. The patient was recommended to avoid heavy lifting for 3 months and to wear an abdominal binder for 6 weeks.
DISCUSSION
Abdominal wall endometriosis is a distinct condition from peritoneal endometriosis, often occurring in isolation. It is my belief that this is the result of portions of endometrium being stuck into the wound at the time of cesarean (inadvertently), though there is some suggestion that pregnancy itself may be causing metaplasia of the fascial tissues into endometriosis. That said, given that we also see it at port sites in women who have had hysterectomies morcellated in the abdominal cavity, I suspect that it is from trapped endometrial tissue.
While medical therapy may lead to some symptomatic benefit, resection is generally required to achieve total remission of symptoms. Most cases can be removed with a simple sutured fascial reconstruction, but larger masses may require mesh reconstruction as we see in this case. In complex cases, it is critical that a surgeon experienced in complex hernia repair is present and involved in the case. I have done many complex cases, and each repair is different depending on the location, depth, and size of the mass. Some are done with mesh, some with native tissue component separation technique, and some with suture alone. While a gynecologist is usually required to make the right diagnosis, they may be unequipped to make the appropriate repair once the mass is entirely removed. Unfortunately, this often leads to inadequate resection if a surgeon is intimidated by the size of the hole they are creating as they start to resect a mass. For this reason, I recommend preoperative MRI in order to fully understand the extent of the disease and to plan an appropriate surgery. In this case, MRI clearly demonstrated that the resulting defect would be substantial, would involve removal of a significant portion of fascia, and would be to inferior to do a component separation closure. As such, my general surgery colleague and I planned preoperatively to do a permanent mesh anchored to cooper’s ligaments, similar to what we would be done in an mesh inguinal hernia repair.
It is not clear from literature what sort of mesh should be used in these cases. We are mostly directed by the experience of our general surgery colleagues in hernia repairs. Lightweight polypropylene tends to scar in over time and eventually will be replaced with scar tissue with relatively little residual tissue. Heavyweight mesh is stronger, but may become encapsulated over time and may be more likely to get infected. If the peritoneal cavity is exposed, a coated mesh is likely superior as the inferior surface of such a mesh will not stick to bowel. A completely biologic mesh may be appropriate for superficial defects that involve only a small portion of the anterior rectus sheath. Such a mesh is often associated with seroma formation, however, and likely will result in less facial strength than a permanent polypropylene mesh.
****************
Dr. Fogelson is available for clinical consultation at Pearl Women’s Center in Portland, OR. http://www.pearlwomenscenter.com. 503-711-1883
