Dyspareunia is not restricted, however, to mesh reinforcement in the posterior compartment. Anterior compartment repair also can be associated with dyspareunia, especially if the posterior axis deviation of the vagina is disturbed.
Posteriorly, there actually may be an advantage to mesh reinforcement in that it provides broad support of the upper vagina without the narrowing impact of midline plication.
Posterior mesh reinforcement also enables us to integrate the repair with effective apical support.
The importance of apical support is central to the case for total repair. The apex has been shown to be involved in the majority of cases of pelvic organ prolapse, and in fact, anterior prolapse is often the secondary consequence of an apical defect.
There is increasing appreciation for the notion that total repair is all about integrating apex repair with coverage of the anterior and posterior compartments, or about reaching the apex through the anterior repair. Unfortunately, only a fraction of prolapse repairs—17%, it has been estimated—has included apical treatment.
In dealing with an anterior defect, the only way to adequately treat the apex using first-generation mesh kits (those that entered the market prior to 2008), therefore, has been to employ mesh in the posterior compartment as well. Through the posterior compartment, the mesh can be attached to the sacrospinous ligament (SSL), enabling true level-one support.
Some surgeons have alternatively modified the anterior kit procedure to be able to place the mesh arms through the sacrospinous ligament.
To understand why some patients experience apical prolapse after anterior vaginal wall mesh kit operations, Dr. J. Delancey's pelvic floor research group at the University of Michigan used MRI to look at the relationship between anterior mesh kit suspension points along the arcus tendineus fascia and the upper vagina in asymptomatic women with a uterus and normal support. They reported at last year's annual AUGS meeting that about one-quarter of the anterior vaginal length was uncovered or unsupported during Valsalva when the arcus tendineus is the most cephalad support.
The second generation of mesh kits—those released in 2008, as well as some that are yet to be released—incorporate SSL fixation through the anterior approach. The incorporation of SSL fixation provides greater coverage of the anterior vaginal wall without the need to enter the posterior compartment. This redefines the term total repair and allows a more tailored approach to the posterior compartment.
In addition to providing apical support, total repair offers an opportunity to prevent gap failure. When one compartment is reinforced and not the other, enough force can be displaced from the stronger compartment to the unreinforced compartment to cause “sequential prolapse” over the ensuing years. (Think of squeezing one end of a balloon.)
In many of the case series on prolapse surgical outcomes, much of what is referred to as failure is really untreated compartment prolapse. Epidemiologic data also suggest that approximately one-third of recurrent operations are due to untreated compartment prolapse (Am. J. Obstet. Gynecol. 2003;189:1261–7).
Interestingly, most surgeons acknowledge that the abdominal sacral colpopexy—as it has been performed in recent years, with the evolution of materials and refinement of technique—is a highly successful treatment for pelvic organ prolapse. Yet these surgeons may not fully appreciate why this surgery is successful.
The operation's success, it can be argued, is due to the fact that the sacral colpopexy is an abdominal delivery system for a grafted repair—in essence, a total mesh procedure. The use of the sacral promontory is a technique choice and not the reason for success. It's the full graft coverage that really makes the treatment work. Most of us find the procedure is more likely to fail when there is incomplete graft extension.
Tips for Total Repair
The best way to prevent vaginal epithelial complications, most notably mesh exposure and/or stiffening, is to pay strict attention to proper dissection and full-thickness incisions, good tissue handling, and flat and unfolded—but loose—placement of the mesh.
These aspects of total repair are difficult to quantify, and experience thus comes strongly into play. There is a visually recognizable layering to the muscularis and epithelium, and the dissection plane is in the loosest areolar connective tissue deep to it. You know it when you are there because the dissection is resistance free and bloodless. This is contrary to the methods taught to most of us during residency training on standard colporrhaphy.
Hemostatic dissection also has the advantage of preventing hematomas. Incisional erosion and perhaps also early failure may be affected.
As when you are preparing to hit the ball in golf, the key is how you start. When hydrodissection (generally with a dilute anesthetic) is properly introduced into the space below the vaginal epithelium, the fluid will preferentially flow in the path of least resistance and find this potential space, dissecting it apart.