Keywords

Introduction

Enterocele is a herniation of the peritoneal cavity forming a sac that protrudes between the uterosacral ligaments at the vaginal apex, which may then descend distally through the rectovaginal septum (Fig. 27.1) [1,2,3,4,5]. It may contain small bowel (enterocele) or sigmoid colon (sigmoidocele) [1, 2, 6, 7]. Its incidence in asymptomatic patients is unknown, and according to some authors, it can range from 11% to 45% in patients with pelvic floor dysfunction and can also be seen in up to 10% of healthy females on defecography [1,2,3, 6, 8]. It occurs more frequently in older or multiparous women and in those with a history of hysterectomy [1, 2, 4, 7, 9].

Fig. 27.1
figure 1

Enterocele

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The onset of enterocele may be multifactorial [9]. It is associated with pelvic floor injury, obstetric trauma, straining from constipation, increased intra-abdominal pressure, prior hysterectomy, and the effect of hormonal changes in the connective tissue of the pelvis [2, 4, 7, 9]. The most frequent type of enterocele occurs when a pelvic organ prolapses (usually the uterus or rectum) pulling down the cul-de-sac, thus creating a traction enterocele [1, 3]. On the other hand, pulsion enterocele may result from chronic abdominal pressure increase leading to protrusion or eversion of the rectal or vaginal wall [3]. Acquired cases are seen after pelvic surgery especially after hysterectomy (18–25% of patients develop enterocele at some point after hysterectomy) in which the cul-de-sac is widened by anterior displacement of the vagina [1, 3, 7, 10]. Finally, congenital enterocele represents less than 1% of cases and results from abnormal development of the rectovaginal septum [1, 3].

Symptoms at presentation are usually nonspecific and include false rectal tenesmus, evacuation difficulty, pelvic pressure, lower abdominal pain, and fecal incontinence [1, 3, 4, 7, 9, 11, 12]. It may be suspected with the presence of pelvic pressure or vaginal bulging, which has a clinical sensitivity for the diagnosis of only 50% [11, 12]. These symptoms may be exacerbated by increasing intra-abdominal pressure especially in the upright position [9]. Some authors have pointed out that the subjective “bearing down” symptoms are often related to mesenteric traction due to the presence of the bowel or omentum in the hernia sac [7]. According to some authors, it is hard to define the typical clinical features of enterocele because most patients have concomitant pelvic floor abnormalities, such as rectocele or intussusception [9].

Diagnosis

The diagnosis of enterocele is based on identifying a hernia sac between the vagina and rectum [7]. This can be achieved by a combined vaginal and rectal digital examination (preferably in the standing position) utilizing a bivalve vaginal speculum ideally with transillumination of the rectovaginal septum with a light source through the rectum, where the small bowel between the rectum and vagina will block the transmission of light [7]. It has been recently described that a pelvic exam showing vaginal bulging has a sensitivity of 50%; however it is often difficult to distinguish rectocele from a true enterocele protruding at the level of the vaginal vault [1, 5, 9, 12, 13].

Solitary presentation is rare, and most cases are associated with rectocele or prolapse of other pelvic organs and/or abnormal descent of the pelvic floor [1, 6]. Most cases are diagnosed during pelvic floor evaluation of other pathologies with conventional defecating proctogram (defecography), dynamic magnetic resonance imaging defecography, or cystoscopy/ureteroscopy [1, 4, 9, 12].

Dynamic Evacuation Proctography (Defecography)

It remains as the gold-standard diagnostic procedure , even though it may miss up to 20% of enteroceles [12, 14]. This study offers a dynamic view of the rectum, pelvic floor muscles, and anal sphincters by filling the rectum with contrast and simulating defecation [15]. It may show the direct compression of the rectum by enterocele which makes rectal emptying difficult [16]. This study has the advantages of being an easy to perform cheap, and readily available diagnostic tool. Nevertheless, it has some limitations including that it is observer dependent, requires usage of ionizing radiation, provides images only in the lateral plane, and does not accurately assess soft tissues [11, 14, 17].

Enterocele is classified according to the depth of small bowel descent determined by defecography: Grade I above pubococcygeal line, Grade II located below the pubococcygeal line and over the ischiococcygeal line, and Grade III when it is below the ischiococcygeal line [3].

Dynamic Magnetic Resonance Imaging Defecography

It is an alternative study with high sensitivity (100%) for diagnosing enterocele [12, 18, 19]. In contrast to conventional defecography, this study does not use ionizing radiation, is not observer dependent, and allows assessment of soft tissue and the three pelvic compartments simultaneously with multiplanar imaging [13, 14, 18]. Nonetheless, it is expensive and not as frequently available as conventional defecography [12, 14].

Dynamic Transperineal Ultrasound

Recently, the use of dynamic transperineal ultrasound has been described. It offers the advantage of being a noninvasive and nonirradiating office procedure with sensitivity comparable to that of dynamic defecography for the diagnosis of a range of pelvic floor disorders [12, 20]. Several studies have shown that ultrasound is better tolerated than defecation proctography and it is considerably less expensive [21,22,23,24]. It is thus likely that ultrasound will replace defecography as the initial investigation of choice in women with posterior pelvic floor symptoms [20].

Cystoscopy

Cystoscopy is useful only to differentiate an enterocele from cystocele [13].

Treatment

Surgical treatment is reserved for symptomatic cases or vaginal or rectal ulceration [1]. The approach may be vaginal or abdominal [3,4,5, 7, 25]. The goal of enterocele surgical repair is excision or obliteration of the peritoneal sac with approximation of the uterosacral ligaments in the midline [1, 4, 5, 9, 13, 26]. This obliteration may be carried out synchronously with an abdominal procedure being performed for any coexistent pathology or, more commonly, accompanying a vaginal approach for hysterectomy or cystocele/rectocele repair [3, 4, 25, 27]. When it is performed at the time of vaginal hysterectomy (McCall culdoplasty), the uterosacral ligaments are incorporated into the closure of the peritoneum and upper vagina after the uterus is removed; this aims at preventing subsequent enterocele recurrence [7, 26,27,28,29].

Because enterocele presents due to weakened vault support, the vaginal vault must also be resuspended [13]. Vaginal vault suspension can be performed through transvaginal reattachment of the uterosacral ligaments (McCall culdoplasty), the sacrospinous ligament, or the iliococcygeus fascia and/or muscle to the vaginal apex [13].

In sacrospinous fixation, a posterior vaginal incision is made and extended to the top of the vagina [13, 27]. The sacrospinous ligament running from the ischial spine to the sacral bone is identified, and two sutures are placed through the ligament and secured to the top of the vagina resulting in increased support to the upper vagina without vaginal shortening; this can be performed unilaterally or bilaterally (Fig. 27.2) [13, 27,28,29]. This technique should be considered at the time of vaginal hysterectomy, when the vault descends to the introitus during closure [29]. Several systematic reviews have shown that sacrospinous fixation is a highly effective procedure with low recurrence and complication rates and good patient satisfaction [30,31,32,33,34]. This procedure carries the risk of a high incidence (8–30%) of postoperative anterior compartment prolapse and stress urinary incontinence, presumably due to posterior fixation of the upper vagina which predisposes the anterior compartment to excessive intra-abdominal pressure [29]. There is no evidence that bilateral sacrospinous fixation or fixation using permanent suture material is associated with lower recurrence rates [29]. Long-term follow-up studies have reported that prolapse symptoms are present in up to 16% of women at 2–15-year follow-up [29]. This procedure may not be the appropriate therapeutic choice for women with a short vagina and should be carefully considered in women with preexisting dyspareunia [29, 35].

Fig. 27.2
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Sacrospinous fixation

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For fixation of the vaginal apex to the iliococcygeus fascia and/or muscle, one or two sutures are placed into the iliococcygeus fascia and/or muscle just anterior to the ischial spine [13]. In patients not sexually active, it is performed without the need of creating a vaginal incision, by placing a monofilament permanent suture at full thickness through the vaginal wall into the muscle [13]. The use of a polypropylene mesh to support vaginal vault suspensions has been reported with high success rates [13].

Abdominal sacrocolpopexy is considered the gold-standard procedure for vaginal vault prolapse treatment [7, 13]. It is performed through an incision in the lower abdomen or laparoscopically [27]. Suspension of the vaginal apex to the sacral promontory with or without a mesh can be performed [13]. The mesh is secured to the sacrum and the peritoneum is sutured over the mesh (Fig. 27.3) [27, 29]. A systematic review of observational studies reported long-term success rates of 78–100%, with intestinal mesh erosion in 2–11% of the cases [29]. Although this procedure requires an abdominal incision and there is a risk for bleeding from the sacral promontory and postoperative ileus may occur, the resultant anatomy carries the lowest recurrence and least risk of sexual dysfunction and dyspareunia [13].

Fig. 27.3
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Abdominal sacrocolpopexy

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Vaginal Versus Abdominal Approach for the Surgical Repair of Enterocele

According to recent literature, although the vaginal approach offers less morbidity, it is documented that up to 20% of these patients present recurrence and/or dyspareunia and is associated with greater risk of ureteral injury as well [1, 9, 13, 16, 29]. Nevertheless, most studies report that both approaches offer successful results in about 80% of the cases [1, 29]. Some studies comparing abdominal sacral colpopexy versus vaginal sacrospinous colpopexy report that the former was associated with significantly lower rates of recurrent vault prolapse, less postoperative stress urinary incontinence and less postoperative dyspareunia at the price of longer operative and recovery times, and higher cost than for vaginal surgery [29]. On the other hand, they report no statistically significant differences in patient satisfaction, number of women reporting prolapse symptoms, reoperation rates for stress urinary incontinence, and reoperation rates for prolapse [29]. Vaginal sacrospinous colpopexy resulted in a reduction in operative time, it was less expensive, and patients had an earlier return to their daily activities [27, 29].

Laparoscopic Versus Open Abdominal Sacrocolpopexy

Laparoscopic sacrocolpopexy can be as equally effective as open abdominal sacrocolpopexy in selected women and may require mesh application. It can be performed in combination with other vaginal procedures to correct prolapse of other organs [29]. One multicenter randomized controlled trial (RCT) compared open abdominal sacrocolpopexy versus laparoscopic sacrocolpopexy and showed that the potential advantages of laparoscopic sacrocolpopexy were significantly less intraoperative blood loss and shorter hospital stay [29]. In contrast, a single multicenter RCT compared open and laparoscopic sacrocolpopexy in the treatment of pelvic organ prolapse without significant differences found for operative time, adverse events, or quality of life among the study patients [27]. Other studies concur with these findings as well [36,37,38].

Mesh/Graft Repair

Some techniques require the routine use of grafts or a mesh to bridge the gap between the vaginal cuff and the concavity of the sacrum [27]. This can be a synthetic mesh (e.g., a permanent polypropylene or absorbable polyglactin mesh) or a biological graft [27]. Biological grafts can be autologous (such as fascial sheath), alloplastic (e.g., porcine dermis), or homologous (e.g., cadaveric fascia lata) [27].

In one trial, abdominal sacral colpopexy with either absorbable cadaveric fascia lata graft (Tutoplast) or nonabsorbable (permanent) monofilament polypropylene mesh (Trelex) were compared. There were no recurrences in either group; however, the failure rate (recurrence at any other vaginal site) was significantly higher (32%) in the fascial graft group than in the mesh group (9%). There were no vaginal erosions in the fascial graft group, but 3.7% had mesh-related erosion in the nonabsorbable mesh group [27]. De Ridder et al. compared two types of absorbable mesh, polyglactin (Vicryl) inlay versus porcine dermis graft (Pelvicol). The failure rate at 25 months of follow-up was significantly greater in the Vicryl group (31%) when compared with the Pelvicol group (9.5%) [27]. In another RCT, Natale et al. compared polypropylene mesh (Gynemesh) repair with porcine dermis graft (Pelvicol) repair. At 2 years, significantly fewer women had anterior vaginal wall recurrence (28%) in the mesh group, whereas 44% of the porcine graft group recurred [39].

In a RCT that compared laparoscopic sacrocolpopexy vs. transvaginal mesh repair in women with vaginal vault prolapse, the women in the laparoscopic sacrocolpopexy group had longer operative time, shorter hospital stay, and quicker return to daily activities with significantly greater patient satisfaction at 2-year follow-up [40]. Another RCT compared transvaginal sacrospinous fixation repair with and without a mesh with 12-month mean follow-up and showed higher recurrence rates in the non-mesh vaginal sacrospinous fixation group without significant difference in quality of life between groups [41]. The limited evidence available on transvaginal mesh kits does not support their use as first-line treatment, and if considered, women should be fully informed of the permanent nature of the mesh and about potential mesh use complications, some of which are serious and have long-term effects that can be difficult to treat [27, 29].

Summary

Enterocele is a herniation of the peritoneal cavity associated with pelvic floor injuries and surgical procedures. Surgical treatment is reserved for symptomatic cases. The goal of the repair is to provide obliteration of the peritoneal sac with approximation of the uterosacral ligaments in the midline using multiple available abdominal techniques.