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Fecal incontinence is associated with 20 to 40% of the patients with pelvic floor prolapse. Successful management of fecal incontinence requires not only an understanding of anorectal function but also a thorough understanding of pelvic floor anatomy and how pelvic floor prolapse affects fecal continence. Imaging techniques have been instrumental in visualizing pelvic floor prolapse and have helped correlate surgical findings. Stabilization of the perineal body appears to be a key component to the success of pelvic floor repair and fecal continence, but the optimal repair is far from being established.
Anal continence is dependent on several factors and has been thoroughly reviewed by several authors.1,2,3 However, pelvic floor integrity is often neglected in the discussion of the treatment of fecal incontinence. There is a 20 to 40% association between pelvic floor prolapse and fecal incontinence,4,5,6 and although fecal incontinence affects both sexes, its association with pelvic floor prolapse affects women exclusively. Fecal incontinence in the setting of pelvic floor instability may be related to several factors other than a primary anal sphincter defect. The loss of anatomical support of the rectum may result in various degrees of prolapse and rectoceles resulting in ineffective or obstructive defecation and may present as symptoms of fecal seepage and fecal incontinence.7 Hence, any woman who presents with fecal incontinence decades after her obstetric history deserves a thorough evaluation of the pelvic floor.
Evaluation of patients with fecal incontinence and pelvic floor instability requires not only a thorough understanding of the pelvic fascia, ligaments, and muscles but also of the dynamic changes of the pelvic floor during prolapse. The current concept of pelvic floor prolapse is likened to a boat in dry dock.8 The water supporting the boat represents the pelvic floor musculature and the moorings represent the ligaments and fascia. The loss of musculature support leads to a weakening of the ligaments and fascia resulting in organ prolapse and dysfunction. It is beyond the scope of this article to adequately discuss the pathologic changes of the fascia, ligaments, and muscles, but they can be reviewed in several other references.9,10,11
The loss of pelvic organ support results in a descent of the bladder, vagina, and rectum akin to herniation described by Moschowitz.12 The loss of the “anchoring” of the perineal body leads to ineffective closure of the sphincter mechanism, rectocele, and anterior rectal wall intussusception, all of which are found on physical exam and seen on cystodefecography.13
Dynamic study of the pelvic floor with cystodefecography and magnetic resonance imaging (MRI) has enabled us to better understand the changes occurring during organ prolapse.14,15 Pioneering work of Berglass and Rubin in 1953 with levator myography showed that descent of the pelvic organs is associated with enlargement of the levator hiatus.16 Moschowitz had earlier observed that such levator hiatal enlargement was associated with a sliding hernia resulting in rectal prolapse.12 The association of enteroceles often found in rectal prolapse further supports the concept of a herniation of the pelvic floor. Mellgren and colleagues17 found that the presence of enterocele on defecography was associated with rectal intussusception (55%) and rectal prolapse (38%). However, pelvic floor prolapse is rarely limited to one organ or compartment abnormality. Maglinte and Kelvin18 showed that 95% of the patients evaluated for pelvic organ prolapse had more than one compartment abnormality. Others have shown that failure to recognize multiorgan abnormality may result in failure of surgical treatment.19 Dynamic MRI can provide anatomical details of pelvic floor defects, but its main limitation is that patients are evaluated in the supine position while straining. Despite this limitation, Kaufman and associates20 showed that combining dynamic MRI with cystodefecography can result in a 41% change in the treatment plan.
Radiologic findings of pelvic floor prolapse correlate well with known surgical observation of the patient with prolapse, namely, diastasis of levator ani, deep cul-de-sac redundant sigmoid colon, patulous anal sphincter, and loss of horizontal position of rectum and its sacral attachment.21 Clinical presentation of these findings are best seen when the patient is asked to strain. Signs of pelvic floor instability are noted with cystoceles descending at the introitus and bulging within the lumen of the vagina which may reflect an enterocele or rectocele. Bidigital examination of both the rectum and vagina can help distinguish the two. However, physical exam can detect only 16 to 54% of the enteroceles found on cystodefecography.22,23 Anorectal examination of the puborectalis muscle in regard to its prominence, tone, and motion may reveal the degree of the degenerative changes from chronic prolapse and neuropathy. Digital assessment of rectocele height and perineal laxity may provide clues about the degree of rectal descent. Currently, the Pelvic Organ Prolapse Quantitation (POPQ) developed in 1996 by the American Urogynecologic Society, the Society of Gynecology Surgeons, and the International Continence Society24 is the most widely accepted means of measuring prolapse, but it has not gained acceptance within the colorectal society because it fails to measure rectal prolapse and perineal descent. The lack of a unified, standardized method of measuring prolapse between the various specialties underscores the importance of a team approach to the management of pelvic floor problems.
Although medical management can play an important role in easing symptoms of fecal incontinence, the added component of pelvic floor prolapse is by and large treated with surgery. In general, surgical approaches to the patient with pelvic floor prolapse are divided into abdominal, vaginal, or perineal. An accepted axiom in medicine, elegantly put by Moschowitz,12 is “The more remedies there are suggested for the cure of a malady the less the likelihood of the efficacy of any particular one.” Evaluation of the effectiveness of the different surgical approaches to pelvic floor repair has been hampered by our lack of a universally accepted method of quantifying pelvic floor prolapse and the failure of communication between specialists. These obstacles are beginning to change; in 2001 the National Institute of Child Health and Human Development convened urologists, gynecologists, and colorectal surgeons to help standardize terminology of pelvic floor prolapse.25 There is an increasing recognition that urinary and fecal incontinence not only coexist in 35 to 50% of the patients26,27 but that combined repair is cost-effective and safe.28 In our practice we routinely involve both urologist and gynecologist in the evaluation of our patients with pelvic floor prolapse.
Our surgical approach to pelvic floor prolapse and fecal incontinence is dependent on the extent of the prolapse and the cause of the fecal incontinence. Examination as detailed previously is complemented with anorectal manometry, pudendal nerve studies, endoluminal ultrasound, cystodefecography, MRI, and consultation with a urologist or gynecologist. Selection of diagnostic tools and consultations with other specialists are dependent on the findings, clinical suspicion of prolapse, and need for documentation of the degree of impairment. In patients who have complete pelvic organ prolapse (Fig. 1), referred to by Eugene Sullivan29 as Tetralogy of Fallout, no diagnostic tests are needed. However, others may present with more subtle findings and we have found cystodefecography to be very helpful in evaluating the pelvic floor. The findings of enteroceles extending below the pubococcygeal line on cystodefecography are highly suggestive of pelvic floor prolapse. The importance of repairing pelvic floor prolapse with or prior to sphincter repair is supported by our recent study. Twenty-eight women with fecal incontinence and pelvic floor prolapse were followed for a mean of 33.8 months; the results showed that anal continence is better achieved if pelvic floor repair is performed prior to or in conjunction with sphincteroplasty rather than sphincteroplasty alone, 71% versus 45% (unpublished data).
Over the past 30 years, Sullivan and coworkers7 have developed a technique to repair pelvic floor prolapse without the resection of organs; this is called Total Pelvic Mesh Repair (TPMR). See Figure Figure2.2. A 10-year report of the procedure was published in 2001. The repair utilizes a polypropylene mesh to resuspend the perineal body, rectum, vagina, and bladder to their normal anatomic alignment. The key concept of the TPMR procedure is the placement of the mesh to secure the perineal body to the sacrum. The perineal body is the focal point of where pelvic muscles and fascia attach themselves, and it is suspended to the sacrum by the uterosacral ligament.30,31,32 The mesh reconstitutes the fascial attachments and reinforces the endopelvic fascia. Hence, perineal descent represents a fascial laxity or defect of pelvic floor. Controversy still exists as to whether this laxity is a result of loss of pelvic muscle integrity, changes in the collagen, or actual defect of the rectovaginal septum.8
In the TPMR, fixation of the perineal body is accomplished with the use of a Cobb-Ragde Needle (V. Mueller, Deerfield, IL). After the rectovaginal plane has been dissected down to the rectovaginal sulcus (where the rectum meets the posterior and distal aspect of the posterior vaginal wall), the needle is placed at the center of the sulcus. The position of the needle is confirmed by placing one finger in the anorectum and the other in the vagina (Fig. 3). The needle is pushed through into the vagina, at the base of the introitus, anterior to the perineal body. The ends of one Prolene suture are threaded through each of the eyes of the Cobb-Ragde blade and pulled into the pelvis. Bilateral sutures are placed on the parietal fascia of the levator ani, anterior and lateral to the rectum, within the same plane as the suture placed to secure the perineal body. These two lateral sutures help open up the mesh and fix the rectocele. The sacral attachment is secured onto sutures placed at S1–2. The mesh is cut into a trapezoid shape, although we often cut a slight curve into the mid aspect of the mesh to accommodate the rectum, and placed to the left of the rectum. The polypropylene mesh Marlex® is selected based on its characteristic of fibroblast ingrowth, which helps to strengthen the endopelvic fascia.33
After sacral-perineal mesh is secured, two strips of mesh cut ~1 cm wide and ~10 cm long are secured on each side of the sacral-perineal mesh, anterior to the rectum. They are then tunneled lateral to the vagina, deep to the peritoneum, and lateral to the bladder to secure onto Cooper's ligament in the space of Retzius. A more detailed description of the procedure can be found in the work by Sullivan et al.7 The two lateral struts provide support for the vagina and bladder. Patients who have urinary incontinence often have a bladder neck repair concomitantly with our repair. In the past 4 years we have added a piece of mesh on the anterior vaginal wall and secured it to the two lateral vaginal struts to help support the apex of the vagina (Fig. 4); we have called this addition the Sullivan strut.
In our reported 10-year experience of the TPMR technique, we had 78 women (38%) who presented with fecal incontinence and pelvic floor prolapse; 66 (85%) had complete resolution of fecal incontinence, 5 (6%) improved, and 2 (3%) were no better or worse. Five (6%) were lost to follow-up. Postsurgical evaluation of some of our patients with cystodefecography showed correction of enterocele, rectocele, cystocele, and rectal prolapse, but we have found 3 patients with an enterocele descending posterior to the rectum. In these patients the cystodefecography showed a complete loss of the puborectalis curvature, suggestive of loss of levator ani integrity. All 3 patients had complained of defecation difficulty, but none has elected to proceed with further correction. We postulate that our mesh network helps strengthen the endopelvic fascia in the rectovaginal septum but fails to provide support to the posterior rectum in those patients who have complete atrophy of the levator ani. We envision a mesh cut in the shape of a horseshoe placed behind the rectum with the two arms tunneled anteriorly, similar to the two struts in our TPMR, and secured bilaterally onto Cooper's fascia.
Not all patients with fecal incontinence and pelvic floor prolapse need a complete overhaul of the pelvis. Prolapse of the pelvic floor is a gradual process of relaxation affecting various pelvic organs at different degrees. The various perineal or anorectal techniques of lifting up the rectum (i.e., the Delorme procedure) or vagina (i.e., anterior and posterior colporrhaphy) have their role in stabilizing the pelvic floor, but their role in improving fecal continence is not well documented.