April 24, 2009 Leave a comment
An enterocele is a hernia of the peritoneal pouch of Douglas extending caudally between the vagina and rectum. It usually contains small bowel with or without omentum. Nichols described four types of enterocele:
- Congenital enterocele, the least common, occurs when the anterior and posterior peritoneal folds fail to fuse during fetal development.
- Pulsion enterocele is caused by a chronic increase in intra-abdominal pressure.
- Traction enterocele occurs when a pelvic organ, for example the uterus, bladder, or rectum, prolapses and causes traction on the vaginal vault and peritoneum.
- Iatrogenic enterocele occurs after hysterectomy, when excess peritoneum remains or the pouch of Douglas is not adequately closed. It may also occur after any procedure that alters the vaginal axis.
The two types of enterocele that urologists most often encounter are traction enterocele associated with anterior vaginal wall prolapse such as cystocele and iatrogenic enterocele that follows surgery on the anterior vaginal wall. Traction enteroceles often present with a concomitant cystocele and stress incontinence in any patient who has previously had a hysterectomy. It may be part of a total vaginal eversion. Iatrogenic enterocele is not uncommon after surgery for stress incontinence and has been reported in 3% to 17% of cases.
In order to understand the pathophysiology of an enterocele, one must first consider normal pelvic anatomy. The levator plate provides the primary support for the pelvic organs and directly supports the rectum and vagina. The distal vagina forms an approximately 45-degree angle with the vertical line while the proximal vagina forms a 110-degree angle and sits almost horizontally over the levator plate. The distal vagina is supported primarily by perivaginal or pubocervical fascia (which is a portion of the levator fascia) and its attachment to the tendinous arch. This proximal portion of the vagina is also anchored along with the cervix over the levator plate by the cardinal and uterosacral ligarnents, which are attached to the tendinous arch and sacrum, respectively. When there is an alteration in this support, commonly seen after hysterectomy, enterocele may occur.
An enterocele usually appears as a mass bulging from the vagina. If the uterus is in place, the enterocele will appear posterior to the cervix. However, more commonly it is seen as a bulge from the apex of the vagina after hysterectomy. Larger enteroceles can be seen bulging out of the vagina introitus. A systematic examination of the vagina and pelvis is the first step in the proper diagnosis of an enterocele. The major differential diagnosis is cystocele and high rectocele. An enterocele may exist independently or in combination with these other forms of pelvic prolapse. It is also important to ascertain if the vaginal vault is prolapsed, as this will affect the type of enterocele repair performed.
The extent of prolapse is first evaluated with the patient in the lithotomy position. The posterior blade of a vaginal speculum may be used to retract the posterior vaginal wall to view the anterior vaginal wall. At this time, the presence of urethral hypermobility, stress incontinence, and cystocele may be assessed. The patient should be instructed to cough and strain during these maneuvers. Next, the blade of the vaginal speculum is rotated to retract the anterior vaginal wall. The posterior wall and vaginal vault are inspected. Prolapse of the posterior vaginal wall can be observed readily with the bladder retracted out of the way. If the patient has not undergone a hysterectomy, the uterus can be evaluated for prolapse and movement. In posthysterectomy patients, support of the vaginal vault must be assessed. A rather large enterocele can occur posterior to the well-supported vault, or the entire vagina may be everted.
Although large enteroceles are often obvious, smaller ones associated with rectocele may appear as a high continuation of the rectocele bulge in the posterior vaginal wall. An enterocele may distinguished from a high rectocele by bimanual examination. A finger may be placed in the patient’s rectum, and she is instructed to cough or bear down. The impulse of the enterocele may be felt against the fingertip as it would during the examination an inguinal hemia. With the index finger in the rectum and the thumb in the vagina, an increased thickness in the rectal vaginal septum may be felt as the enterocele is trapped between the two fingers. This maneuver can be repeated in the standing position (with one foot elevated on a stool) if there is any doubt about the diagnosis. Standing the patient provides a true impression of the degree of prolapse experienced during daily activity. When there is difficulty in distinguishing between cystocele and enterocele, a cystogram with anterior–posterior, oblique, and lateral resting and straining views can be done to help delineate the bladder. Sometimes it is difficult to determine the degree of cystocele and enterocele strictly by physical examination, and this may not be sorted out until the time of surgery.
INDICATIONS FOR SURGERY
Generally, the degree of an enterocele and the amount of discomfort it causes are the indications for surgery. Small enteroceles are often asymptomatic and need not be treated. However, there is a tendency for enteroceles to increase in size over time if left untreated. Larger enteroceles that prolapse outside the vaginal introitus are usually quite uncomfortable. Generally, treatment is driven by patient’s symptoms of discomfort, incontinence, obstructive voiding, and constipation. In cases of severe vaginal prolapse, erosion and ulceration of the vaginal wall may occur, causing a great deal of discomfort. When other pelvic surgery is being performed, e.g., stress incontinence surgery, an enterocele of any size should be repaired at the same time, as they are likely to worsen postoperatively.
When surgery is contemplated, it is important to consider all of the anatomic abnormalities including vaginal vault prolapse, cystocele, urethral hypermobility with or without stress incontinence, rectocele, and the presence of a uterus. Also, the patient’s degree of sexual activity will play a role in the type of surgical procedure performed. Age may also influence the type of procedure being performed. Finally, if the patient might undergo a laparotomy for other pathology, this may influence the type of surgery performed, as a transabdoniinal procedure may be elected.
A nonsurgical alternative for treatment of enterocele and pelvic prolapse is the use of a pessary. Pessaries come in a variety of shapes and sizes and are fit on a trial-and-error basis. Some patients with severe pelvic prolapse are unable to hold the pessary. In others, pessaries are found to be uncomfortable or to cause vaginal infections. A pessary can be used as a temporizing measure until surgery can be performed or as a chronic management of enterocele and pelvic prolapse in patients who do not wish surgical intervention. The type of pessary used is based on the degree of enterocele, presence of a uterus, and other coexisting pathology.
Another surgical alternative for enterocele treatment is colpocleisis, in which the entire vaginal canal is closed. This may be elected in the very elderly or in patients who have failed multiple attempts at repair.
Once the patient has elected to have surgery, preoperative preparation is simple and consists of a modified bowel prep, which can be performed at home. The day before surgery the patient can begin on a clear liquid diet and also should take an oral laxative such as citrate of magnesia. The evening before surgery the patient should take a self-administered enema. As in all vaginal procedures, the patient receives broad-spectrum antibiotic prophylaxis perioperatively. We prefer to use gentamicin and ampicillin, or vancomycin in patients who are penicillin allergic. Doses of antibiotics are given just before the procedure and are continued for 24 hours after the procedure. At this time, the patient is switched to a broad-spectrum oral antibiotic for 10 days.
The choice of the specific type of enterocele repair will depend on several factors. We always prefer a transvaginal repair when possible, as this will reduce morbidity and recovery time. In cases in which laparotomy is being performed for another reason, an abdominal approach is preferred. In selecting the type of transvaginal repair, it is important to note the type and extent of the enterocele. If the vaginal vault is prolapsed, this will require a suspension or fixation of the vaginal vault in addition to the repair of the enterocele. This takes into consideration whether vault prolapse exists and also the degree of anterior vaginal wall prolapse or cystocele. If there is no vault prolapse and no cystocele, a simple repair can be performed. In cases in which there is vault prolapse and cystocele, a vaginal vault suspension is chosen. In cases of vault prolapse with no significant cystocele, a sacrospinous ligament fixation is performed. The sacrospinous ligament fixation can also be used in cases of vault prolapse with cystocele; however, we have found the vault suspension technique to be easier and to yield equal or better results in properly selected patients.
Transvaginal Enterocele Repair
All four variations start with the technique of simple enterocele repair, and other procedures may be performed after this if necessary. The patient is placed in the dorsal lithotomy position and prepped, with attention to adequately scrub the inside of the vagina in preparation for surgery. We usually place an iodoform-soaked pediatric laparotomy pad into the rectum so that it can be easily identified by palpation of the posterior vaginal wall. This is especially helpful when a concomitant rectocele repair is to be performed.
The labia are retracted with silk sutures. If a cystocele repair is to be performed, we usually place a suprapubic tube at the beginning of surgery either by the Lowsley tractor technique or percutaneously. A Scott ring retractor (Lone Star Medical Corporation) is very useful in helping to expose the operative field.
The first step is to isolate, repair, and remove the enterocele sac. This is begun by grasping the enterocele with two Allis clamps and bringing it outside of the vaginal introitus. The vaginal wall is then infiltrated with normal saline to facilitate dissection and separation of tissue planes. A longitudinal incision is made in the vaginal wall along the entire length of the enterocele. The vaginal wall is then carefully dissected away from the underlying pubocervical fascia and enterocele sac. In the initial dissection, care must be taken to stay very superficial and develop the proper plane. This is best accomplished by placing the curve of the Metzenbaum scissors against the vaginal wall. A finger can be placed on the outside of the vaginal wall to stabilize the initial dissection. Once the proper plane is entered, it is usually quite easy to dissect the vaginal wall away from the underlying enterocele sac. Care taken here will prevent early entry into the peritoneal cavity. The dissection of the enterocele is continued all the way to the neck of the enterocele sac. After the enterocele has been completely isolated, the sac is opened, and the peritoneal cavity is entered. At this time, one may see small bowel, omentum, or ovary and fallopian tube in cases where previous hysterectomy without oophorectomy has been performed.
The next step is closure of the enterocele defect or pouch of Douglas. Retraction of the peritoneal contents is best performed using a moist pediatric lap pad and a narrow Deaver retractor. This is assisted by placing the patient in Trendelenburg position so that abdominal organs fall slightly cephalad. The enterocele repair begins posteriorly while the abdominal contents are retracted anteriorly using the Deaver. A #1 PGA suture is first placed through the peritoneum and into the prerectal fascia that overlies the rectum. A circumferential closure of the defect is then performed by placing the pursestring suture laterally in the right in the uterosacral–cardinal ligament complex, anteriorly in the peritoneum, overlying the base of the bladder, laterally on the left in the uterosacral–cardinal ligament complex, and finally again posteriorly in the prerectal fascia. After this pursestring suture has been placed, a second one is placed in the identical structures in close proximity to the first. Care should be taken to place these sutures deep enough to ensure that adequate vaginal depth can be achieved. After the second pursestring suture has been placed, a third #1 PGA suture is placed from the right to the left uterosacral–cardinal ligament complex. This suture helps to reinforce the repair and also will be left tagged to help identify this complex later should it be necessary. After all sutures are placed, the assistant cinches down and places tension on one of the pursestrings while the surgeon ties the other. After this has been tied, the second pursestring is tied in a similar manner, followed by the uterosacral–cardinal ligament suture. The two pursestring sutures may now be cut while the third is left tagged. The excess enterocele sac may be excised, and the ends oversewn with a 2-0 PGA suture. If only a simple enterocele repair is performed, the tagged suture may now be cut. Excess vaginal wall is then excised, and the vaginal wall is closed with a running 2-0 PGA suture incorporating deep tissue to obliterate any dead space. An antibiotic-impregnated vaginal packing is placed for a period of 24 hours.
Enterocele Repair with Vault Suspension
The vault suspension procedure may be used when the vaginal vault has prolapsed and a cystocele is present. The size of the cystocele will determine the choice of vault suspension. For moderate cystocele (grades 2 and 3) with primarily lateral defects, the four-corner vault suspension and cystocele repair is the procedure of choice. When severe anterior vaginal wall prolapse is present with a grade 4 cystocele and a large central defect of the bladder through the pubocervical fascia, vault suspension with repair of grade 4 cystocele is used. These procedures incorporate techniques of two previously described repairs for moderate and severe cystocele.
Four-Corner Vault Suspension
After simple enterocele repair has been completed, the vaginal wall is left open, and the anterior vaginal wall is further infiltrated with normal saline. An inverted-U incision with the apex halfway between the bladder neck and the urethral meatus is made. The sides of the U are extended proximally to the level of the vaginal cuff and the uterosacral–cardinal ligament complex where the previous enterocele repair had been performed. The vaginal wall is then dissected laterally off the glistening surface of the periurethral fascia and out to the pubic bone in a manner identical to that performed for the Raz bladder neck suspension. Once the pubic bone is reached, the retropubic space is entered with sharp dissection, detaching the urethropelvic ligament from the tendinous arch using a curved Mayo scissors. A finger can then be placed in the retropubic space, and any adhesions bluntly lysed. Two #1 polypropylene suspension sutures are placed on each side. The distal sutures are identical to those for a Raz needle bladder neck suspension. They include two or three helical bites of full-thickness vaginal wall without its epithelium, pubocervical fascia, and urethropelvic ligament at the level of the bladder neck. The proximal sutures incorporate two to three helical bites of full-thickness vaginal wall without epithelium at the level of the vaginal cuff, pubocervical fascia, and the uterosacral–cardinal ligament complex. This complex can be identified by placing tension on the previously placed #1 PGA suture, which had been left tagged. After these sutures are placed, tension should be placed on them individually to make sure they are in strong tissue. The patient should be able to be moved on the table by pulling on each suture. The procedure is then repeated on the opposite side. Once these sutures have been placed, a stab incision is made in the anterior abdominal wall at the superior border of the symphasis pubis in the midline. A Pereyra–Raz double-pronged ligature carrier (Cook Urological) is placed in this incision and brought through the retropubic space under direct finger guidance. Each of the four suspension sutures is transferred to the anterior abdominal wall individually, as in other needle suspension procedures. Once these sutures have been transferred, gentle tension is placed to make certain that there is reduction of the cystocele.
Cystoscopy is performed to document that there has been no injury to the bladder and that the bladder neck and proximal urethra elevate and coapt nicely. Ureteral injury is ruled out by having the anesthesiologist give intravenous indigo carmine and observing for efflux of blue from each of the ureteral orifices.
The vaginal wall is closed with a running interlocking 2-0 PGA suture. After closure of the vaginal wall, the previously placed suspension sutures are tied with minimal tension. Antibiotic-soaked vaginal packing is placed, and the small suprapubic incision is closed with a subcuticular 4-0 PGA suture.
Vault Suspension with Grade 4 Cystocele Repair
A vertical midline incision is made in the entire anterior vaginal wall after it has been infiltrated with normal saline. This incision will extend from the midurethra all the way through the vaginal cuff and sometimes into the posterior vaginal wall. As described above, the vaginal wall is then dissected from the underlying cystocele, enterocele, and pubocervical fascia. In these cases, it is usually the bladder that is first encountered. The large cystocele is dissected out almost in its entirety. Once most of the posterior portion of the cystocele has been dissected, the enterocele sac is usually seen. After the enterocele sac is identified, its posterior margin can be dissected off of the vaginal wall. It is extremely important to completely separate the anterior margin of the enterocele sac from the bladder. If this plane is not obvious on initial dissection, it can be seen more easily after the enterocele has been opened. Adhesions of the enterocele sac to the bladder can safely be dissected with a finger inside the enterocele sac. Once the cystocele and enterocele have been completely separated, the retropubic space is entered by perforating the endopelvic fascia as described above for the four-corner vault suspension.
The bladder may be reduced and packed up in its normal position with a gauze sponge so that enterocele repair can be performed first. The enterocele sac is opened, and the peritoneal cavity entered. Once the enterocele sac has been mobilized all the way to its neck and the cystocele is adequately reduced, enterocele repair can be performed (as described above for simple enterocele repair). After completion of the enterocele repair, attention is turned to the cystocele. Anterior vaginal wall and vault suspension sutures of #1 polypropylene are placed. The distal sutures include the urethropelvic ligament, pubocervical fascia, and full thickness of vaginal wall without the epithelium at the level of the bladder neck. The proximal sutures are placed in the pubocervical fascia, uterosacral–cardinal ligament complex (again identified by the previously placed tagged suture), and the full thickness of the vaginal wall without the epithelium. These sutures are transferred to the anterior abdominal wall through a stab incision in the identical manner described for the four-corner vault suspension. Next, the central defect of the cystocele is closed, approximating the attenuated pubocervical fascia in the midline, using a 2-0 PGA suture. During the repair of the central defect, the bladder is kept reduced with either a gauze sponge, which is removed, or PGA mesh, which can be left in place. After completion of the cystocele repair, cystoscopy is performed as above. The excess anterior vaginal wall is closed with a running interlocking 2-0 PGA suture incorporating deep tissue to avoid any dead space. If present, the rectocele is repaired at this time. After closure of the vaginal wall, the suspension sutures are tied with minimal tension. Antibiotic-soaked vaginal packing is placed, and the suprapubic incision is closed with a 4-0 subcuticular PGA suture.
Sacrospinous Ligament Fixation
This technique is used to repair enterocele and vault prolapse in cases in which the anterior vaginal wall is well supported. This commonly occurs after bladder neck suspension or colposuspension. Certainly, one would not want to jeopardize the previous anterior vaginal wall repair by performing a vault suspension. In this case, vaginal depth and axis are restored by posterior fixation of the vaginal vault to the sacrospinous ligaments. The sacrospinous ligament stretches from the ischial spine to the sacrum and is covered by the coccygeus muscle. This procedure may also be used with cystocele repair, but we prefer the vault suspension in this instance.
After simple enterocele repair is completed, the posterior vaginal wall must be opened far enough distally to facilitate dissection to the sacrospinous ligament. When a simultaneous rectocele repair is to be performed, the entire posterior vaginal wall is opened through the perineum. After the posterior vaginal wall is incised in the midline, it is gently dissected laterally from the underlying prerectal fascia for a short distance. Next, the sacrospinous ligament must be identified. This is done by penetrating the right or left rectal pillar (pararectal fascia) sharply and entering the pararectal space. Blunt dissection of the pararectal space can be performed with a combination of finger dissection and the use of deep Breisky–Navratil retractors. This dissection is performed until the sacrospinous ligament is palpated and overlying coccygeus muscle is seen. The Breisky–Navratil refractors will help to expose the ligament. Once the ligament is identified, a #1 PGA suture is placed through the ligament and coccygeus muscle complex 2 cm medial to the ischial spine, which is also identified by palpation. It is important to place the suture in this position to avoid injury to the pudendal nerve and vessels, which run just below the ischial spine. It is also important to include the strong ligament in addition to the overlying coccygeus muscle. Tension should be placed on this suture to make certain that it is in the ligament. A second suture should be placed adjacent to the first. Each of these sutures is then placed through the full thickness of the vaginal wall at the level of the dome, approximately 1 cm apart, and left untied. If a rectocele is present, it is repaired at this time. The dome of the vagina can be directed under finger guidance to the deepest possible portion, where it will be fixed. The vaginal wall is then closed with a running interlocking 2-0 PGA suture, and then the previously placed sacrospinous ligament fixation sutures are individually tied. Antibiotic-impregnated vaginal packing is then placed.
An intra-abdominal approach to enterocele may also be performed. We usually reserve this for when laparotomy is being performed for other reasons. The abdominal approach described by Moschcowitz is similar to the simple enterocele repair that we use except that the approach is from above.1 In cases of vault prolapse, a colposacropexy can be performed using autologous rectus fascia or a synthetic mesh.
After completion of the surgical procedure, the antibiotic-soaked vaginal packing is left in the vagina until the next morning. Patients receive two to three postoperative doses of intravenous antibiotics before they are switched to broad-spectrum oral antibiotic. In the case of simple enterocele repair or sacrospinous fixation, when no suprapubic tube is used, the oral antibiotic is continued for 7 to 10 days. In cases where a suprapubic tube is left indwelling, antibiotics are usually continued until normal voiding resumes and all tubes are removed. Patients are usually hospitalized for 24 to 48 hours. They may resume light activity on discharge and only restrain from heavy lifting, strenuous exercise, and intercourse for 6 weeks.
When the algorithm described above was used for 83 patients, 14% experienced complications.5 Operative complications included one bladder and one ureteral injury. Most of the delayed complications were minor and included suprapubic wound infection (2.5%), cystocele (1.2%), rectocele (1.2%), flap of excess vaginal tissue requiring excision (1.2%), and chronic suprapubic pain (1.2%). In one patient in whom hysterectomy was not performed with enterocele, uterine prolapse developed, and vaginal hysterectomy was done. Other possible complications that did not occur in our series include small bowel or rectal injury, vaginal shortening limiting the ability to have intercourse, prolonged urinary retention, de novo stress or urge incontinence, and pelvic pain from pudendal nerve entrapment following sacrospinous ligament fixation.
We used the above algorithm on 83 consecutive patients undergoing enterocele repair. Forty-nine (60%) underwent simple repair, 25 (31%) had vault suspension with enterocele repair (eight had four-corner and 17 had grade 4 cystocele repair), and seven (9%) had sacrospinous ligament fixation. Overall success (no recurrence) was 86%: 82% for simple repair, 96% for vault suspension, and 86% for sacrospinous ligament fixation. A total of 11 patients suffered recurrence at a mean of 11 months (range 4 to 32 months). Two of these occurred after further vaginal surgery, and one after pelvic trauma. Success for sacrospinous ligament fixation has previously been reported to be 62% to 97%.