Pelvic Organ Prolapse is the herniation of the bladder, rectum, uterus or vagina presenting as a lump at the introitus. Uterovaginal prolapse is traditionally treated with vaginal hysterectomy and pelvic floor repair. Corrective surgery of the vaginal prolapse must aim at objectives to relief symptoms; restore normal vaginal anatomy and restore potential coital function.
However surgeons sometimes face patients who returned shortly after surgery with recurrence of the lump at introitus. This is embarrassing for the surgeon and disappointing for the patient.
REVIEW OF THE ANATOMY AND SUPPORT OF PELVIC ORGANS
The pelvis can be thought of as a three-tiered system of support, consisting of the bony pelvis, the pelvic floor muscles and the endopelvic fascia (1).
In the standing position, the vertebral orientation places the pelvic inlet in almost vertical plane, turning the pelvic cavity almost at right angles to the abdominal cavity, allowing the abdominal organs to push against the pubic symphysis. The bony orientation directs transmission of weight from the upper body to the lower extremities via the hip joint and the head of the femur. The pelvic bones also provide points of insertion for the major muscles of pelvic support.
The pelvic floor consists of a bilateral set of U-shaped muscular sheets known as the levator ani and coccygeus muscles. The levator ani consists of puborectalis, pubococcygeus and iliococcygeus components. Pubococcygeus and iliococcygeus, tonically contracted, form the levator plate, which is the horizontal floor on which the bladder, the proximal two-thirds of the vagina and the rectum rest.
In 1992, J O L Delancey (2) reported an elegant study on 69 cadavers to look at the support of the pelvic viscera. He reported that the bladder, uterus, vagina and rectum were all attached to the pelvic sidewalls by a network of connective tissue strands that are collectively called the endopelvic fascia. The structures that support the vagina can be divided into 3 levels that correspond to differing areas of support (See diagram). The 3 levels of vaginal support are interdependent and continuous with one another. Defects in level I support would result in uterine or vault prolapse. Defects in level II support will result in cystocele and/or rectocele. As the vagina is intimately attached to the adjacent structures at level III, displacements of the urethra, levator ani or perineal body carries the vagina with it.
NON- SURGICAL TREATMENT
Pessaries are the mainstays of non-surgical therapy. They come in all shapes and sizes that may allow tailoring of the pessary to a specific support defect and individual anatomy. However it may be impossible to retain a pessary in patients with weak pelvic diaphragm, large genital hiatus and complete procidentia. Sulak (3) described three types of patients that benefit from pessary use:
1. The patient unfit for surgery
2. One awaiting surgery
3. One who declines surgery
It is crucial to identify the site/level of defect before we start the repair procedure.
Other important factors to consider include damage to the levator ani muscles with resultant increased inclination of the levator plate and the alteration of the vaginal axis after surgery.
(I) Repair of Level I Defects
If surgery is preferred in cases of severe prolapse, additional support of the apical compartment of the vaginal is necessary to reduce the risk of vault prolapse where the uterosacral ligaments are found to be deficient or the vaginal vault is sitting near or outside the introitus after hysterectomy.
Many procedures have been described to increase support to the vaginal vault. These tend to be cul-de-sac obliteration, vault suspensions or a combination of both.
Cul-de-sac obliteration could be done transabdominally as described by Moschowitz (4) or Halban (5) or transvaginally by McCall (6 ).
Many procedures for Vault suspension had been described:
1. vaginally, by hitching the vault to the sacrospinous ligament (sacrospinous
colpopexy ( 7) or iliococcygeus muscle(8 ).
colpopexy ( 7) or iliococcygeus muscle(8 ).
2. or abdominally by hitching the vault to the presacral ligament
3. abdominal vaginal approach e.g. Zacharins procedure(10).
4. laparoscopic approach
Vaginal procedures are generally associated with less morbidity but higher recurrence of prolapse(11). Abdominal procedures are associated with fewer recurrences but there is rare association with severe bleeding from the presacral plexus and 3.3% chance of mesh erosion (12). Abdomino-vaginal approach ahas increased morbidity and high recurrence rate and is not advocated. Lapaproscopic repair of pelvic organ prolapse follow the same principles as above methods but adequate laparoscopic suturing skills are essential and there may be increase in operative time. More prospective clinical trials and long term studies are required.
(II) Repair of Level II Defects
Anterior vaginal wall defects could be due to Central defects, paravaginal defects or both.
Central defects could be repaired vaginally by anterior colporrhaphy but paravaginal defects need to be repaired specifically either by attachment to the cooper’s ligament(13) (abdominally) or the White line and ischial periosteum (vaginally)(14).
Repair of the posterior vaginal is similar to the anterior vaginal wall . Discrete fascial tears is identified & repaired after vaginal epithelium is incised and separated from the underlying endopelvic fascia.
Synthetic meshes had been reported in the repair of cystoceles / rectoceles with good success. The only worry is that of mesh erosion which occur in 2% of patients in one series (15).
(III) Repair of level III Defects
The normal vagina is a collapsed organ. Closure of a gaping introitus by perineal reconstruction is important. However one must not be too overzealous or the patient may complain of dyspareunia.
Repair of pelvic organ prolapse is complex and the surgeon need to understand the anatomy and support of the pelvic organs before planning a site specific repair procedure for the patient. Use of synthetic and non-absorbable sutures decrease the risk of prolapse recurrences but the advantages had to be balanced with the risks of infection, erosion and rejection of foreign bodies by the body.
However despite all precautions taken, recurrence of prolapse can occur. We can do our best to reduce it.
DR ARUKU NAIDU
MD(UKM), FRCOG(UK), CU(JCU)
CONSULTANT O & G AND UROGYNAECOLOGIST